Case neck tension question/issue

[NikA]

Yesterday evening I started reloading 40 S&W cases and found that the case tension on my bullets was very different from my previous experience reloading revolver rounds. I am relatively new to reloading but understand that the 40 S&W has somewhat of a reputation for load issues and would like some input on this before I go off and do anything stupid.

The situation:
Loading Blazer and GFL headstamp 1x fired cases, I found that about ~30-50% of the GFL cases had NO case tension, such that the bullet would seat ~0.005 deeper than the cases with tension. I "adjusted" these rounds with a kinetic puller and thumb pressure to my desired OAL and crimped them as hard as I felt was needed using a push test and a safety margin. Upon examining the rest of my brass, I found more GFL cases that seemed insufficiently sized, so I resized all of them and got essentially the same result. Is this the result of:
1) Cheap brass?
2) Cheap dies? (Dies are Lee and I have heard that occasionally there are QC problems)
3) Some stacking of tolerances? (bullets are MBC 170gr SWC and mic at .402+, so I assume this is not the case)

In my limited previous experience, I can see the bullet bulge the case slightly as it is seated. This is not happening with the bad 40 S&W cases, and is only very slightly visible in the good ones, which I would conclude is the result of inadequate case tension. Are these loads likely to cause an issue when fired?
Thanks for your input.

 

[Cheesewhiz]

NikA, welcome to the forum.

How much have you read up on reloading ammo for semi-auto pistols? There are a lot of things to learn before being able to get them completely right. So much so, that I can't spend all the time needed to write it all down.

You are right, .40 S&W isn't the easiest to do and definitely not the best semi-auto round for a first try. I don't reload .40 S&W but have helped a few guys out over the last few years to get it right.

Are you lubing your cases? If you are, don't lube when applying a taper crimp, they don't mix at all. The lube ends up in the case mouth and you can move/push the bullet easily with a taper crimp in a lubed case.

Speaking of taper crimp are you using one or are you trying to roll crimp? You don't roll crimp semi-auto rounds unless you plan on blowing up your gun. The case mouth is what the round headspaces on. If you roll it you move the headspace point, huge mistake.
....and if you attempt to roll crimp/over crimp with a taper die, a bulge will form and that bulge is not contacting the bullet and therefore there is no tension in that area.

....but before any of this is even considered, the first thing necessary is that the case is sized all the way down to the bottom of the case, a piece of paper should be the only thing that should slip between the bottom of the die and the lowest portion of the shellholder with the ram up

Once a round has been made and found wanting that case is not good until it is resized. It doesn't matter why it needs to come apart, that case needs to be resized, improper length, missing primer, poor neck tension the case will need to be resized. You can set those cases aside and later resize them minus all the decapping hardware so you don't pop a primer.

Remember, the case mouth must headspace in the chamber of the barrel, a roll crimp or too much crimp will prevent this and that is a dangerous round. I would get a Lyman Max Case Gage for .40 S&W so you can check if you are getting it right, they only cost like $15. Some people will tell you to use your barrel from your gun, that's fine for finding rifling interference with a bullet, Over All Length, (OAL) but is dumb as hell for everything else, most chambers are the size of a garbage can compared to a proper gage.

...and if it doesn't check out in the gage, it's junk. Don't make junk.

I would make 5 dummy rounds with no primer or powder, make adjustments and try again 'til you get it absolutely right, you can always take those apart.

 

[NikA]

Firstly, thanks for the welcome. I have been following this forum for a while but have only recently reached the point at which I felt I could ask pertinent questions or offer any knowledgeable opinions.

Although I just started reloading ammunition ~3 months ago, I read extensively on the considerations involved for about 18 months prior to that. I am an engineer by trade and so understand many of the considerations in that context. I feel like I have a fair grasp of the intellectual knowledge, just no experience.

My cases are not lubed as I have a Lee carbide die set. My understanding is that the Lee sets come with a "modified taper crimp" for calibers that headspace on the case mouth, and the crimp I am applying with the FCD is visibly different than those I have made for revolver cartridges, so I believe it is truly a taper crimp. However, I doubt the issue at hand is the crimp, since the bullet tension issue appears in the seating step. As for fully sizing the brass, I live dangerously and screw down the die until it touches the shellholder. I am loading on a hand press at this point and doubt I will have the force/momentum necessary to break a carbide die insert with this setup.

I still don't quite understand why I am not getting proper, uniform tension while seating bullets, but your reply makes me think it might be the tolerances of the Lee dies. They are new, so if need be I can call Lee up and ask them to check them out.

Thanks for the suggestion on the case gage. I considered buying one of these when I started collecting reloading tools, but given that I reload at a very limited rate and already own a copious amount of measuring tools, I figured I could go measure individual rounds if I thought there was a problem.

 

[NikA]

Forgot to say that I did indeed make a couple trial rounds with just bullets and because a limited percentage of the cases that display this problem, this issue came to light after I was already dispensing loads.

 

[Cheesewhiz]

Post up a picture of a finished round, we might be able to see something. I will be honest with you, I normally bail out when someone says they are using a hand press and are having problems. Hand presses are inferior and produce an inferior product. That's not meant to be mean but you are trying to load a round that guys with Dillon presses have issues with, you are really going to fight this until it drives you crazy.

 

[Cheesewhiz]

Thanks, DB for the compliment.

There are some brass cases out there that do create problems, a lot of times it's that the brass get deformed when decapping. So that could be an issue but if he is using one of these, he will always have problems.

https://sp.yimg.com/ib/th?id=HN.608035836119877775&pid=15.1&P=0

 

[NikA]

Please forgive the picture quality, my lighting situation is not the best:

Top round is a GFL case is no tension, center round is a Blazer case with tension, bottom round is a .38 Special that shows same bullet bulge I see in loads that are not a problem. I measured the cases below the bullet but above the case web and got .4248 for the GFL and .4219 for the Blazer, so that would seem to indicate to me a sizing issue.

I know the Lee Hand Press is not the best, but it is unfortunately all I have room for in my current situation. I am actually surprised by the consistency of it given the looseness of the linkage, for mixed .38 Special brass seating depth had a spread of .003 according to my calipers. I do not deprime using the press, I deprime prior to case cleaning using a Harvey Deprimer.

 

[NikA]

Well, I thought linking the image that way would work but I can't see it. The url: http://imgur.com/SO5yHxC

 

[NikA]

 

[Cheesewhiz]

I see a couple of things. Have you checked that a finished round spins freely when you chamber it in the barrel of your gun after you remove the barrel from the gun? SWC's a lot of times need to be seated so the larger diameter of the bullet is barely showing at all, if the round doesn't easily spin in the chamber, the bullet is loaded too long. The other thing is that the crimp is too tight and that may be the tension issue. The edge of the case mouth should shave wax off a candle, like on of those cheese shaver pieces of junk that people get you for Christmas.

The last thing that I can think of is how much are you belling the case? Are you pushing bullet lube up as the round is seated? Can you see it either on the case or the dies

 

[NikA]

I have not checked these particular rounds in the gun, but the dummy cartridge was loaded from the magazine several times with no bullet setback and no chambering problems. The only difference here was the amount of crimp applied. When I removed the barrel from the gun, I cleaned it thoroughly at the same time and noticed that the rifling leade was fairly generous. OAL here is 1.135+, since the load data I have for this type of bullet gives a minimum OAL of 1.13 and this is a load workup.

Like I said, the tension issue shows up before the crimp is applied. I tried measuring just the crimp and got .420+, leading me to believe that it will be sufficient for headspace. Looking down the bullet, I can still see some of the case mouth (i.e., it is not completely pushed into the bullet as a roll crimp would be).

I expand the case until I can seat the bullets without shaving anything. I see no lube buildup on the dies or cases other than what gets on my hands when handling the bullets. I was initially concerned with overexpanding the brass but decided that belling them all more was easier than picking up lead shavings.

What I'm hearing thus far is that this issue can likely be attributed to poor tool tolerances or low quality brass, and since there don't seem to be tolerance issues with other mixed brass, it's looking more like brass than tools.

As far as firing the rounds safely, is there any check I can do short of buying more measuring tools to make sure the cases are headspacing properly? I can drop them in the chamber of the pistol but I don't know that it would be easy to measure where they are headspacing.

 

[Cholo]

I've loaded for the .40 S&W off and on for about 18 years. I don't have a lot of experience with it only loading a couple 1,000 rounds. The chambers in my 2 Kahr's run tight, as do other makes. Your case mouths, after taper crimping, should run no more than .420". Yours seem loose. Try that and let us know how it works. If not, try using some quality brass, trimmed to length.

If I understand correctly, you're using a hand press as opposed to a single stage press like I use. It doesn't bode well with the 40 S&W where .001 can make a difference.

YMMV...

PS: You posted while I was pecking...

 

[WMB30]

NikA What is the length of your cases, and the COL

Bill

 

[contender]

Considering the 40 S&W cal is one of the top calibers used in USPSA competition, I don't think it's any more problematic than others. In USPSA, the folks who shoot it load it as a "major" power factor for scores. (If you don't know what that means, it's the bullet weight, multiplied by velocity, divided by 1000. That number must be at least 165 to make "Major.") It's loaded long, short, & with many different bullets. The general consensus is a good resize, and a good taper crimp, to where the bullet doesn't move.
Good brass is the key to good ammo here.

 

[Cheesewhiz]

Considering the 40 S&W cal is one of the top calibers used in USPSA competition, I don't think it's any more problematic than others. In USPSA, the folks who shoot it load it as a "major" power factor for scores. (If you don't know what that means, it's the bullet weight, multiplied by velocity, divided by 1000. That number must be at least 165 to make "Major.") It's loaded long, short, & with many different bullets. The general consensus is a good resize, and a good taper crimp, to where the bullet doesn't move.
Good brass is the key to good ammo here.

...and I agree that it is used successfully and is a viable round for reloading but many .40 S&W loads are compressed loads or damn close to it. So bullet and powder choice is important, consistency in finished length, a crimp point must be maintained and that also will be determined by the case sizing, squared seating of the bullet and with even the best presses, the base of the case must sit flat so there is little movement as the bullet is seating.

The OP's equipment and component choices are never going to let him get these things consistent enough. Unsorted range pick up brass can be an issue because his "press" will not size them the same because there is not enough force to put things back where they need to be and absolutely need to be every time for every case. The choice of bullet being hardcast and a SWC will fight back during the seating process, Those cases, especially the crappy ones will not hold themselves dimensionally trying to force a .402", hardcast bullet into a short case at a fairly deep depth. A bigger diameter bullet doesn't help much if it's what's reopening the case and removing the case sizing that just was done.

A taper crimp requires a properly sized case, from top to bottom. A good bell, that is neither over or under in diameter to what is necessary for the chosen bullet. The depth of the bell in a short case is a major issue, if you go down too far you just removed half the proper sizing from that case. The crimp won't fix that because the now seated bullet will not allow the case to be squeezed down enough to have any clamping force. You can get away with this with lower powered/less presssure roll crimped revolver rounds, you can't with any taper crimp. Remember this round is short and kinda fat, when the bullet is seated if it does so nice and straight with no wiggling around, the integrity of case tension remains, if it's moving around as it seats, it opens up everything that you just closed down to a proper size. That is also why, with short cases that they sit flat and parallel while the bullet seats or the same damn thing happens. The bullet and the case must stay inline with each other throughout the seating process, otherwise the case wall will hold no tension and the taper crimp is useless.

 

[ilikerams]

Just a thought, when I got my lcp .380, I bought some magtech 85 gr. hps. They were advertised as .355 but every one I measured was .353. Had all kinds of neck tension problems. Using a Lee fcd with more crimp than I thought you would ever need I still had rounds that I could move with my finger. So maybe check the bullets?

 

[NikA]

Have been paying attention to replies on this but just returned from the holiday to the source of the problem.

Cheesewhiz, while I appreciate your input with regards to poor tool quality and questionable brass, I don't think it is productive to dismiss this setup out of hand. As I have stated here, I have not had the same problems reloading other cartridges on this setup, and all my brass is MY brass, as in I have fired it in my guns and not purchased it used or scrounged it. I have not had consistency problems with seating other bullets.

As far as this issue goes, I think I have now confirmed that DixieBoy was correct in his assessment of the brass issue. These dies were actually purchased to load 10mm (.40 seemed like a safe first test but I don't have much demand for it), and it occurred to me that I do have 10mm 1x fired brass of known quality on hand that was sized and expanded with these tools. Seating a bullet in this brass produced the case tension I expected, so I am satisfied it is a brass issue and not a tool issue. FWIW, I did measure the thickness of the .40 brass and noted that the GFL cases were thicker than the Blazer, so perhaps they are more resistant to sizing (greater springback effect) and this is where the problem originates.

All that remains now is to fire these first attempts and see if they are really worth the time I put into this exercise.

 

[Mobuck]

I really like to see that "bulge" at the base of the bullet after loading. That means you have "maximum" neck tension.

 

[Cheesewhiz]

Have been paying attention to replies on this but just returned from the holiday to the source of the problem.

Cheesewhiz, while I appreciate your input with regards to poor tool quality and questionable brass, I don't think it is productive to dismiss this setup out of hand. As I have stated here, I have not had the same problems reloading other cartridges on this setup, and all my brass is MY brass, as in I have fired it in my guns and not purchased it used or scrounged it. I have not had consistency problems with seating other bullets.

As far as this issue goes, I think I have now confirmed that DixieBoy was correct in his assessment of the brass issue. These dies were actually purchased to load 10mm (.40 seemed like a safe first test but I don't have much demand for it), and it occurred to me that I do have 10mm 1x fired brass of known quality on hand that was sized and expanded with these tools. Seating a bullet in this brass produced the case tension I expected, so I am satisfied it is a brass issue and not a tool issue. FWIW, I did measure the thickness of the .40 brass and noted that the GFL cases were thicker than the Blazer, so perhaps they are more resistant to sizing (greater springback effect) and this is where the problem originates.

All that remains now is to fire these first attempts and see if they are really worth the time I put into this exercise.

You made it quite clear in your first post that you are an engineer, I'm assuming mechanical, then you of all people should know the issues with deflection in an insertion/alignment process and the built in aftereffects to consistency of a product produced within these compromises and self induced limits. These hand presses have been around for a long time and they will run some cartridges just fine and dandy but when life throws you a curveball you need to realize the damn thing is coming. The ram on a lee hand press is what? 3/4"? the ram on a quality press is at least 2" of prehardened 4140 steel normally with the further hardening of a hard chrome finish.

I'm happy that you found that some/a certain brass allows you to get it to work to the best of your knowledge right now but I guarantee that my press with a proper set of dies could run the worst of your brass and make completely fine rounds that would work in most pistols. If you had actually had chosen better and proper components, such as a better and easier bullet to use and learn from, that along with far better reloading equipment would allow me to claim with confidence that they would work in any .40 S&W gun that was maintained and within factory spec.

Some of the stuff I've written in my posts to this thread you will never find in any reloading manual, it only comes from making damn good decisions and shear luck and the ability to quickly find exactly were the issues lie.

Remember when I said earlier in this thread that I normally bail out when I find that the OP is using a hand press, now I remember why.

Added Note: I just read in this last post of yours, I took several takes on it, confused I'd say, that you are running 10mm dies to run 40 S&W, my god man you sure know how to make things difficult.

 

[NikA]

Got a chance to go the the farm and fire these rounds over the holidays. Terrible leading but no pressure signs tell me that they were OK except for the bullet\powder combo, so the search for the ideal load continues. I have more or less decided to throw out the GFL brass at this point since used 40 brass is so cheap anyways. I now have the tools to definitively measure these differences if anyone is interested (and I will gladly do a metallurgical study on used brass if anyone wants it).

Cheesewhiz, while I appreciate your reloading experience, it is clear that your engineering knowledge is lacking. I am a materials engineer, and while I might not be able to comment on insertion processes per se, I would wager that most of the alignment in cartridge reloading happens in the dies. It would be unfair of me to point out all of the misconceptions you consider as fact, suffice to say that the considerations for single stage vs. progressive presses are very different in terms of the largest contributions to misalignment. I would gladly PM you sources for this information if you have further interest. As you say, a lot of what I know "you will never find in any reloading manual,", simply because these items are not written on the same level as engineering documents, despite the materials and pressure considerations involved. As for the 10/40 dies, I suspect that you know that every major die manufacturer offers dies with an adjust range that allows for the reloading of both 40 S&W and 10MM auto cartridges.

 

[Rick Courtright]

I am a materials engineer, and while I might not be able to comment on insertion processes per se, I would wager that most of the alignment in cartridge reloading happens in the dies.

Hi,

I don't claim to be an engineer, though I did get to drive a train once... that was kinda cool, if off topic.

This "alignment" thing is something that's intrigued me for a number of years, especially as the vendors make such a big deal of it. So a few years back I got to talking to a buddy who IS quite familiar with the types of manufacturing processes some of our reloading operations mimic. He laughed, and asked what a "press" does. Well, it pushes things...

Yup, according to him, that's all it does, while the real work is done inside the die, and once the cartridge enters that die, it's not going anywhere else, so it sounds like you'd win your wager. Of course, he did emphasize the value of a smooth, steady motion to allow the brass to "self-center" at the start rather than just "jamming it in" as I've seen some loaders do. To illustrate, he asked if I could tell which ammo I'd loaded on which one of my various presses, using the same dies. Actually, I couldn't!

Then he brought some ammo out to the desert next time we got together he'd loaded on a little Lee Reloader press. You know, the one so many self-styled "experts" are fond of saying is an absolute piece of junk? Like many folks, I've got one--he's got at least four of 'em. That ammo was some of his silhouette competition ammo, and took out a ram-sized rock at a measured 205 yds just as well as any I'd ever seen him shoot on the range (he shot AA in whatever IMSHA's box stock revolver class is back when I was spotting for him, using both .357 Mag and .44 Mag. Which is a way of saying he's a heckuva lot better with a handgun than I am.)

He doesn't use those little Lee presses cuz he's a cheapskate. He just likes 'em better for certain chores than the Bonanza Co-Ax and Dillon 550 also sitting on the bench. And it was hard to argue with his results. At least for me! I guess this just serves to reinforce the important lesson I learned long ago about there being many ways to do most of our reloading chores, which all get us to the same end point.

Rick C

 

[triggerpull]

Are you seating and crimping at the same time? I'd separate the two processes just to ensure reliability--for really tight tolerances it might even pay to get the separate factory crimp die (I have lots of em and think they are great).

 

[PO2Hammer]

Cheesewhiz, while I appreciate your reloading experience, it is clear that your engineering knowledge is lacking. I am a materials engineer, and while I might not be able to comment on insertion processes per se, I would wager that most of the alignment in cartridge reloading happens in the dies. It would be unfair of me to point out all of the misconceptions you consider as fact,

I guess you're too educated to gain from my 20 years of handloading experience as well.

 

[NikA]

I had no intention of stepping on toes here, PO2Hammer, simply pointing out that the statements made were not consistent with good engineering practice. Specifically, nothing in the following paragraph makes any sense to me except to contradict my previous assertion that the Lee hand press is "good enough":

"You made it quite clear in your first post that you are an engineer, I'm assuming mechanical, then you of all people should know the issues with deflection in an insertion/alignment process and the built in aftereffects to consistency of a product produced within these compromises and self induced limits. These hand presses have been around for a long time and they will run some cartridges just fine and dandy but when life throws you a curveball you need to realize the damn thing is coming. The ram on a lee hand press is what? 3/4"? the ram on a quality press is at least 2" of prehardened 4140 steel normally with the further hardening of a hard chrome finish."

Specifically, since you think I'm being dismissive, I'll break it down for you:
1) As I said, I'm almost certain that the alignment in reloading happens in the dies. I say this because a simple approximation of the reloading process on the press allows hundredths of an inch misalignment in the press linkage and possibly tenths of an inch misalignment in the single stage shell holder. Since I've never heard of anyone getting close to this amount of misalignment PROVIDED THE COMPONENTS ENTER THE DIE, I guess that the radiused surfaces of the die entrance allow some degree of misalignment to be compensated by the die design. Further, I hear benchrest shooters talk about runout in thousandths of an inch from different sets of rifle dies, which is much smaller than the play in any press.
2) Deflection of a 3/4" piece of steel bar from a small car is on the order of thousandths of an inch (e.g. a bottle jack ram). This is clearly an order of magnitude less play than the press linkage. Even with mechanical advantage of a lever, I doubt I can exert the same force as a small car on the press ram in question.
3) As far as I can tell, ALL single stage presses have rams of approximately 3/4" diameter, because they are meant to match the shellholder diameter, which is 3/4" for all die sets I have seen. So clearly someone is talking about something else entirely here, which is counterproductive to the conversation. But in any case, my engineering knowledge tells me that the hardness condition of the steel and the surface treatment to keep it from wearing (hard chrome per cheesewhiz) have very little to do with the stiffness of the material, which is the property that goes into deflection of the ram. That's ignoring that a single stage press is essentially an axial loading with minuscule deflection as opposed to a progressive press which might have large enough displaced loads to generate some deflection (hence the larger diameter ram, I'm thinking).

Now I'm not saying that I can't learn anything from people with years more experience in this area than I have. I am saying that when I look at a problem, I am specifically trained to evaluate things like materials limitations, deflection, misalignment, and so forth and determine whether they are a factor in the quality of the final product. When I evaluate the Lee hand press, I find that while it is often a hassle to line up cases and bullet with the play from the shellholder, I see no evidence that this contributes to differences in the sizing of the cases and the resulting neck tension, which is specifically what my initial question was about. When I pointed this out, I was dismissed because I'm new to reloading and experienced reloaders have learned to purchase better equipment.

I'm almost certain that y'all are just as capable as learning from me as I am from you, and it'll cost you a lot less than the years of schooling that go into an engineering degree.

 

[Justice B. Swift]

In my 30 years reloading I've developed some prejudices. In my opinion you had two strikes against you before you ever pulled the handle on your first reload.
1) I've had very "mixed" results with lee dies - hate 'em, won't use 'em. Buy RCBS or Redding.
2) Dump the questionable brass in favor of good quality brass and save the headaches. Starline is always good.
Once you have done those two things you likely will have no further issues. Sounds like you have "studied-up" and have a pretty good idea what to do, you just need quality materials going in. Stick with a modest taper crimp for your "auto" ammo as was mentioned earlier, as the case headspaces on the case mouth. You should be fine. Happy Loading.
-Just B.S.-

 

[Cheesewhiz]

Specifically, since you think I'm being dismissive, I'll break it down for you:
1) As I said, I'm almost certain that the alignment in reloading happens in the dies. I say this because a simple approximation of the reloading process on the press allows hundredths of an inch misalignment in the press linkage and possibly tenths of an inch misalignment in the single stage shell holder. Since I've never heard of anyone getting close to this amount of misalignment PROVIDED THE COMPONENTS ENTER THE DIE, I guess that the radiused surfaces of the die entrance allow some degree of misalignment to be compensated by the die design. Further, I hear benchrest shooters talk about runout in thousandths of an inch from different sets of rifle dies, which is much smaller than the play in any press.

Ask anyone with a progressive press or someone that knows of someone with a progressive press that has gotten just slightly out of time and they will tell you that the dies don't do all the alignment and a press in this condition will produce a cartridge that exhibit some of the issues that you have and even worse. The cases and bullets will run as normal but that slight misalignment will cause a whole lot of issues, your conclusion that all alignment is done in the dies is specious and wrong.

2) Deflection of a 3/4" piece of steel bar from a small car is on the order of thousandths of an inch (e.g. a bottle jack ram). This is clearly an order of magnitude less play than the press linkage. Even with mechanical advantage of a lever, I doubt I can exert the same force as a small car on the press ram in question.

This analogy and comparison doesn't really mirror that of a ram of a reloading press and you will find that a well made hydraulic bottle jack has a precision ground, hard chrome finished shaft/ram. More on that in a bit.

3) As far as I can tell, ALL single stage presses have rams of approximately 3/4" diameter, because they are meant to match the shellholder diameter, which is 3/4" for all die sets I have seen. So clearly someone is talking about something else entirely here, which is counterproductive to the conversation. But in any case, my engineering knowledge tells me that the hardness condition of the steel and the surface treatment to keep it from wearing (hard chrome per cheesewhiz) have very little to do with the stiffness of the material, which is the property that goes into deflection of the ram. That's ignoring that a single stage press is essentially an axial loading with minuscule deflection as opposed to a progressive press which might have large enough displaced loads to generate some deflection (hence the larger diameter ram, I'm thinking).

I mentioned what my progressive press utilizes as a ram and it's make up as a point in comparison. Yes, my press has five stations so a larger diameter ram would be needed to stop what? Deflection of the shell plate base and ram. Now for the meaning and usage of a thin coat deep hard chrome finish of a shaft or ram on an easily machined pre-hardened round stock steel shaft such as 4140 steel. Normal 4140 tool steel has a Rockwell hardness of 40 to 55C, a properly applied hard chrome finish isn't a plating per se but a treatment to make the shaft have far better bearing surface properties and makes it less likely to produce friction and galling. It also will raise the surface Rockwell hardness to a range of 70 to 75C. It has been found that this surface hardness increase, especially on a radius or fully round substrate will actually make that shaft/ram stronger and reduce flexing, twisting or deflection of that shaft. I urge you to find an old Mechanical Engineer with a good background in machine design and the building of heavy machinery and you will find he probably agrees with that point.
As far as most single stage presses using 3/4" shafts that is wrong, most use 1" or greater diameter shafts for their rams. You probably know that an increase in diameter of any shaft is not a 1:1 math equation but a multiple based on application and outside considerations. It is normal to expect a 50% increase in strength in some axis's with a 25% increase in diameter that could be as high as 4 to 1 in certain designs based on the necessary bearing surface increase and support and length of stroke.


Now I'm not saying that I can't learn anything from people with years more experience in this area than I have. I am saying that when I look at a problem, I am specifically trained to evaluate things like materials limitations, deflection, misalignment, and so forth and determine whether they are a factor in the quality of the final product. When I evaluate the Lee hand press, I find that while it is often a hassle to line up cases and bullet with the play from the shellholder, I see no evidence that this contributes to differences in the sizing of the cases and the resulting neck tension, which is specifically what my initial question was about. When I pointed this out, I was dismissed because I'm new to reloading and experienced reloaders have learned to purchase better equipment.

I'm almost certain that y'all are just as capable as learning from me as I am from you, and it'll cost you a lot less than the years of schooling that go into an engineering degree.

I won't comment on this last part much but to point out most of the guys on this forum are not rubes, toothless rednecks and shade tree mechanics. You'll find that this forum has a fair amount of professionals that not only achieved a higher level of education than you but have decades and decades of experience in their chosen profession and of course, in life.

Oh.....and NikA, please leave me out of further discussion in this thread I'm sorry I ever got involved in the first place.

 

[Rick Courtright]

I mentioned what my progressive press utilizes as a ram and it's make up as a point in comparison. Yes, my press has five stations so a larger diameter ram would be needed to stop what? Deflection of the shell plate base and ram. Now for the meaning and usage of a thin coat deep hard chrome finish of a shaft or ram on an easily machined pre-hardened round stock steel shaft such as 4140 steel. Normal 4140 tool steel has a Rockwell hardness of 40 to 55C, a properly applied hard chrome finish isn't a plating per se but a treatment to make the shaft have far better bearing surface properties and makes it less likely to produce friction and galling. It also will raise the surface Rockwell hardness to a range of 70 to 75C. It has been found that this surface hardness increase, especially on a radius or fully round substrate will actually make that shaft/ram stronger and reduce flexing, twisting or deflection of that shaft. I urge you to find an old Mechanical Engineer with a good background in machine design and the building of heavy machinery and you will find he probably agrees with that point.
As far as most single stage presses using 3/4" shafts that is wrong, most use 1" or greater diameter shafts for their rams. You probably know that an increase in diameter of any shaft is not a 1:1 math equation but a multiple based on application and outside considerations. It is normal to expect a 50% increase in strength in some axis's with a 25% increase in diameter that could be as high as 4 to 1 in certain designs based on the necessary bearing surface increase and support and length of stroke.

Hi,

Cheese, I'm not an engineer nor a machinist/metallurgist/production type guy, so I'm not here to argue but to learn as I often do, from folks who actually do this stuff every day in their lives.

Having said that, I'm reminded of the old "mine's stronger than yours" stories told by Mr. Lee about criticisms of his early turret press. From memory (dangerous?), apparently at the time press manufacturers were in some kind of a "war of massiveness" advertising campaign that made some think his press would simply break into little pieces if tasked with a job like sizing a large magnum cartridge, so the story goes he turned the four legs that join the head and base of the machine (probably about 1/2" stock to begin?) down to 1/8" diameter, and started sizing big cases. No biggie, the press performed the task just fine!

So we move forward 30-40 years, and it seems we're back to the "bigger is better" wars again. What's old is new? Since I'm a confirmed single stager, I realize the design parameters of a progressive machine pose challenges not found with single stage machines, but ask that we look at just the most basic aspects of the design for now. And that leads to some questions:

First, how much force are we actually putting into the handle and sending to the ram? I don't have a way to measure how hard I'm pushing on the handle, but saw something in the instructions for a Lee collet die that a fair amount of force on the handle, about 25 lbs, is required to operate the collet. If that's a correct figure, I'd guesstimate the force I put into the handle in most normal operations may run only half that! There are very few operations I do which require much force at all... but let's use that 25 lbs as a base line.

So, I get out my tape measure and try to figure the leverage involved. On one of my presses, the initial ratio is about 7:1, so that turns my 25 lb input into about 175 lbs force at the ram face. I'm sure there's some multiplication factor involved with compound leverage linkage I haven't included. That's still nowhere near the "tons of force" I see mentioned over and over. Perhaps my math is deficient? I'll never argue my math skills are great, yet I don't see enough force to "flex" press frames as we often see people claim.

Ok, for now I've got my 175 lbs of force to do something with. How much pressure is there at the end of the ram? With the exception of my Rock Chucker, all my presses have the "old size" rams, which run around 3/4" or 13/16". Using my limited math skills, I get a pressure of around 350 psi on the head of the ram. For comparison, that's roughly the same pressure a 125 lb lady puts on her heels when wearing high heels, assuming she can balance on them alone, shifting all the pressure from the balls of her feet! That, of course, is offset thru the linkage, and a little calculator work shows a couple of linkage points where the pressure's a bit higher, but overall, it would appear to my untrained eye there's just not that big a load on any of the components of the system. I'm guessing that's what Mr. Lee was trying to illustrate?

So... assuming my math isn't THAT bad, what are the "working" advantages of bigger rams, hard chrome finishes, lots more "bearing surface" in the press body itself, and similar "features" to the AVERAGE guy? Unless one plans on running a half million or so rounds thru his press--which we know some do!--is there a signficant decrease in wear over "traditional" sized components simply treated to a spot of oil now and again? For a single stage application, I'm gonna rely on my buddy's assertion that a little play in the ram, shellholder, etc., serves a valuable purpose in allowing the brass to self center as it enters the die, at least until someone shows me what part of the picture I haven't viewed yet (remember, we're still talking single stage equipment.) Added all together, this kinda negates the need for a lot of the "bigger is better" mentality in my mind. Unless, of course, one simply likes playing with precision machinery, and has the budget for such nice equipment as Corbin's and some other top drawer mfrs sell, in which case all bets are off!

Can you help educate me some more, please?

Rick C

 

[Cheesewhiz]

Rick, I can bring up an application that I was involved with not all that many years ago but long enough.
It was a drive roller assembly for pulling a perforated EDD (extra deep draw) steel that is very soft and pliable about 40mm wide and a thickness range from .010" to .018".The upper or lower drive roller had either a knurled surface or another sort of friction profile and the other polished smooth, the rollers were approximately 100mm in diameter, hardened to 75C Rockwell hardness and about 75mm of contact area with the product metal. They slid onto 40mm hardened shafts (60C) with just the slightest of slip fit (.0003"), both roller shafts were mounted in double cup and cone heavy duty precision bearings in large pillow blocks on both sides with the upper roller assembly in movable slide assemblies with very little side play as they rode on barrel bearing slide units and the rollers nested.
The drive rollers were pre-gapped at .005" so they could not come in contact with each other, just the driven material only. The force applied was by two 1" hydraulic cylinders, running anywhere from 600 to 1000 psi. The entire assembly was less than 10" across it's width. This application ran at a rather slow speed of about 12' a minute. If you looked at this thing, you would swear it was over engineered to the maximum.
We found that the strip that was driven always displayed more force on one side over the other and I started checking things with a couple of the other guys and our chief (an old time everything engineer, who was absolutely brilliant), we found that the lower stationary roller assembly was deflecting across a width of 100 mm between .012" to .020", I almost found this impossible but that brilliant old engineer just said "never be surprised by deflection or run out, expect it". That was good enough for me, I have taught myself to always find out why something was designed the way it was. Was it a lack of modern materials or manufacturing techniques or did these guys know something I'm not seeing.

Rick, you know that the possibility of misalignment can cause issues with reloading and as I had said earlier in this thread that little press will run some stuff just fine most probably but pushing something beyond the boundaries of certainty and you will always find a flaw in your thinking.

That's all I got to say about that.

Added note: "correction, correction please", you have to be a Cubs fan from years back to get that one. I do have more to say, Rick, if the ram diameter or the design of the press didn't matter why does Lee make a single stage press that is about a third step up from the Handloader that is an "O" frame and uses a 1 1/8" diameter ram?

 

[NikA]

If I read your situation correctly, you're talking about deflection due to loading perpendicular to the shaft axis. I am talking about deflection due to loading in line with the shaft axis. If the loading is 100% in line with the shaft axis, there should be no deflection, only possibly beam buckling. If the loading is in line with the shaft axis but displaced, there will be a slight torque that may cause deflection of the end, but it will be minuscule, as I pointed out, in comparison to the looseness of the linkage of the press.

I do stand corrected- surface treatment can affect the compression state of the surface and make it more resistant to deflection if forces are applied perpendicular to the shaft axis. However, this effect is based on one side of the shaft being predominantly in compression. In the press ram situation, the entire shaft should be in different states of compression, so the effect is tiny. I don't think it plays a significant role here.

 

[NikA]

So I sat down and worked this out, thoroughly. Suffice it to say that although I was correct in my assertion, it was a more complicated problem than I imagined, so I'm not surprised that there is come confusion.

Some measurements:
-Lee hand press has a ram that is .81 inches in diameter with a hole .405 inches in diameter drilled through it. I assumed no hardening, surface treatment, etc. because I stand by my statement that they do not significantly contribute. I did assume the hole was in the center of the ram.
-The ram extends 3.5 inches from the bearing surface in the press body. I did not factor in the shellholder or the slight difference in the ram at its top to accommodate the shellholder.
The distance from the pivot pin to the ram pin is ~1.75 inches, the distance from the lever end to the pivot is ~11 inches. I'll call the mechanical advantage for this lever 8 for a margin of error, and I'll assume if you stand on the thing you can apply 200 pounds of force on it (although you'd likely break the aluminum casting before you could exert that load). That gives a ram force of 1600 lbs.

Worst case loading scenario, you get an off-axis load at the edge of the ram (which is the same diameter as the shellholder, remember), so I assumed that this is what happens. I also assumed that this is the lowest modulus steel Lee can find (lower even than low carbon steel), which comes in with a Young's modulus of 28 ksi.

Now, I won't go through the entire calculation because it's dull and there's not really a good way to express it here, but if you look up the "secant formula" (for column loading) online or in the appropriate engineering textbook and use it correctly for a column with one fixed end (the ram end in the press bearing surface) and one free end, you get a maximum deflection of 0.000136 inches. This deflection is linear with load displacement from the axis, so feel free to calculate it for however far you want: even at an inch out, it's still in the ten-thousandths of an inch. Since I can move the press ram in the bearing surface of the press body, I'd guess that there is at least 0.001 inch of play there, not counting play from the shellholder assembly. I am positively NOT concerned about the deflection of this "tiny" ram. I WOULD be concerned about play in the linkage, because that is the major contributing factor to misalignment in reloading presses, at least from the press end of things.

THAT is an engineering analysis of THIS situation, and NOT some problem someone else had with deflection in insertion processes that was a completely different loading situation, NOR another type of press that has a related but somewhat different loading situation.

FYI, the O-type press is designed because it doesn't have off-axis forces in the cast areas of the press which are notably less strong than the ram. C-type presses are inherently unbalanced such that a casting flaw can be exposed when a large amount of unbalanced force is placed on the press body. This type of flaw is likely where your press would break if you elected to stand on it to carry out the test above repeatedly.