Redding Profile Crimp Die

[islander]

Discovered that my 38 spl rounds are being shortened by the crimp die. That's right - the bullet is seated to the specified OAL, right on the nose, but then the crimp die, set for a minimal roll crimp, shortens the round by anywhere from 0.005 to 0.008".

Discovered accidentally by measuring OAL after crimping, which I never do. Went and measured my entire stock of loaded rounds, and sure enough all of them were shorter than specification by around 0.005" on average. Yikes!

I slipped a bullet through the crimp die and it slid through without any binding, so it must be that the crimp die is compressing the case as it crimps it - but there is no buckling whatsoever so this is very strange.

Called Redding tech and they have "never heard of such a thing", but then suggested compensating by seating the bullet higher. Little suspicious advice for an unheard of problem, but it was probably just helpful advice, as weird as it is. Not bashing Redding, and they said they would talk to an engineer and get back to me.

I am not very experienced but am meticulous about reloading, from equipment to weights and measurements, and I trim cases to within 0.002" tolerance. My case belling is minimal. Cases are from 2 different lots so it's not an anomaly with the cases. Press for crimping is a new Lee classic cast iron. I use a quality dial caliper. I lightly lubed the case mouth as instructed by Redding. Crimp is minimal. All evidence points to the profile crimp die as the culprit.

So, any of you guys using this crimp die, have you ever experienced similar results, or can you measure the OAL AFTER crimping and post your findings?

 

[gmaske]

When you crimp, the case is always shortened just a tad by the rolling in of the end of the shell. .005 sounds like it might be the ball park figure. I'm not nearly as exacting as you but if you know your case overall length before you crimp I'll bet they are shorter after the crimp is set.

 

[islander]

Thanks for the reply and yes any type of crimp is going to shorten the case, but that's not the issue - the crimp die is seating the BULLET deeper. Small amount yes, but something to keep in mind especially if you are loading hot or maximum loads. I would realy like to hear from users of this crimp die and learn if this is normal.

 

[gmaske]

A little more to the point....If the crimp grabs the bullet as it is rolled in it will pull the bullet down with the crimp. If you are doing a heavy roll crimp you could very well be compressing the case a tad also.

Hey! You live in the Gables! I grew up in the Grove! That was before all the beautiful people "discovered" it. Howdy neighbor! :wink:

 

[Rick Courtright]

Hi,

Are you crimping in a cannelure?

If so, my cocktail napkin drawing to show myself what you're describing says a crimp placed "low" in the cannelure will probably cause more "shortening" than one placed "higher."

That appear to be just the geometry of the situation on a piece of paper: the "roll" presses against the shoulder of the cannelure as I drew it. And that WOULD pull the bullet down into the case some. How much would probably depend on how "firm" a crimp you've got the die set to produce.

I'd have to play around w/ some different seating depths to see whether I got it right or if being left-handed and dyslexic it having its effects. Again.

If my drawing's correct, it might not be any fault of the die. But I won't say for sure: I use the Lee Factory Crimp Dies, and don't know if they work the same way the Redding die does...

But it's worth playing around for the curious!

Rick C

 

[contender]

I would think that a .005 to .008 shortening in a 38 spl would not be an issue unless you are really max loading the 38's and using them in a revolver not capable of accepting +p ammo.

 

[islander]

GMaske the Grove! I lived worked and played hard in the Grove for many years. Also, this may surprise you but I lived not too far from Colorado, in Casper, back in the 70's. Still a little wild back then.

Courtright your napkin sketch may be right on the money - my load OAL puts the case mouth close to the bottom edge of the cannelure (Hornady XTP), the case mouth grabs the edge of the cannelure as the roll starts, and seats the bullet slightly as the crimp is completed. I tested this and learned the bigger the crimp the more the bullet is seated by the crimp die. But I have not tested whether starting the crimp further up the cannelure eliminates the bullet seating.

 

[islander]

Contender you are correct this issue is negligible with my start loads, fired in a GP100. But it came as a surprise and it's something else to deal with and compensate for, especially as you mention for max loads.

I'm just tryin' to get it right, don't like surprises. Well, not in handloading anyways!

 

[gmaske]

GMaske the Grove! I lived worked and played hard in the Grove for many years. Also, this may surprise you but I lived not too far from Colorado, in Casper, back in the 70's. Still a little wild back then.

That's funny, you went East and I went West. I lived in the Grove from about 1961 till 1972. I use to hang out at Dinner Key Marina in my teens. That whole area was really cool back then. I need to go back one of these days just for the memories.

 

[Sonnytoo]

Thanks for the reply and yes any type of crimp is going to shorten the case, but that's not the issue - the crimp die is seating the BULLET deeper. Small amount yes, but something to keep in mind especially if you are loading hot or maximum loads. I would realy like to hear from users of this crimp die and learn if this is normal.

Yes, mine seats the bullet deeper also. Like the company advised, Ijust seat it a bit higher. I'm crimping into a crimp groove so easy to tell when it's right. If too deep, I use an inertia puller to pull the bullet out another 0.030 or so and then readjust. It all works out fine.
BTW, I seat to a depth where I visually check the crimp in the crimping groove, and not necessarily to a particular specification. And I don't find .005-.008" to be critical. I realize different strokes.
Sonnytoo

 

[WIL TERRY]

The only crimp dies I have seen do this were NOT adjusted correctly.
I own several of the first REDDING PROFILE CRIMP DIE ever made for several different calibers.

 

[islander]

Wil sorry not the case here I know how to adjust and set dies. As soon as I get the slightest roll on the case mouth the bullet seats deeper. Let me ask you have you ever measured the OAL after seating the bullet and then after crimping? Could you please?

 

[gerryb158]

It seems very logical that when you roll crimp a straight wall case such as the .38 Spec, as the crimp is applied the case will shorten. The more the roll crimp the shorter the case will become. If the case lip is in contact with the bullet during the crimping process (as I think is normal) the bullet will move along with the case lip and therefor end up seated deeper. Now my question is - does it matter? I seriously doubt that seating a bullet .005 in. deeper on a truly maximum load in a .38 is going to cause the destruction of any servicable revolver. If case shortening by roll crimping worries you I'd suggest you get a taper crimp die. Or better yet, a Lee Factory Crimp Die. The Lee die crimps by compressing the lip of the case inward through the use of a three (or four) peice collet and does not shorten the case - or seat the bullet deeper. Sheeeesh, with "short" seated bullets, magnum primers and lead dust I don't know how I've survived all these years! Just lucky I guess. So far. Gerry

 

[gmaske]

Sheeeesh, with "short" seated bullets, magnum primers and lead dust I don't know how I've survived all these years! Just lucky I guess. So far. Gerry

Bout sums it. :wink:

 

[islander]

It seems very logical that when you roll crimp a straight wall case such as the .38 Spec, as the crimp is applied the case will shorten. The more the roll crimp the shorter the case will become. If the case lip is in contact with the bullet during the crimping process (as I think is normal) the bullet will move along with the case lip and therefor end up seated deeper. Now my question is - does it matter? I seriously doubt that seating a bullet .005 in. deeper on a truly maximum load in a .38 is going to cause the destruction of any servicable revolver. If case shortening by roll crimping worries you I'd suggest you get a taper crimp die. Or better yet, a Lee Factory Crimp Die. The Lee die crimps by compressing the lip of the case inward through the use of a three (or four) peice collet and does not shorten the case - or seat the bullet deeper. Sheeeesh, with "short" seated bullets, magnum primers and lead dust I don't know how I've survived all these years! Just lucky I guess. So far. Gerry

Case shortening is not the issue. Bullet seating is. Crimp dies are not "supposed" to seat the bullet - Redding's instructions say that the bullet must be seated to the proper depth before crimping. And it's not just .005" it goes up to .008" and that's with the lightest crimp. I tried some heavier crimps and the bullet was seated about .015". You may not care about this and that's great, but I like to know everything that my reloadng equipment is doing, in detail.

 

[gerryb158]

I think you are not seeing the forrest because the trees are in the way. "Case shortening" IS the issue, because that is what is happening. You are cerainly correct, crimp dies are not "supposed" to seat the bullet and I don't believe this type of die does "seat the bullet." I've explained what is happening as rolling the case mouth is actually drawing the bullet deeper into the case. And I'm certain you can vary the depth simply by changing the amount of crimp. You can measure the varience, right? You are also correct in that "I don't care about this" but thought I'd offer what I thought might be helpful to you. Just keep on plugging along, you'll be fine with that Redding die. If you "seat" the bullet to the proper depth, as Redding suggests, and then apply the correct amount of crimp your OAL should be darn near perfect! Gerry

 

[Sonnytoo]

Gerry is correct when he says that the act of crimping will pull the bullet down into the case along with the brass. THIS IS NORMAL. In your REDDING instructions, it recommends adding case lube "near the case mouth, applied every few rounds,...because there is sliding action at the taper." So REDDING even says, unless you have perfect lube, you must expect that the crimping action will pull the bullet down a bit.
I leave my bullet a bit "high" in the case at first and then crimp it and have a visual. My brass should finish at the top of the crimping groove. If the bullet is still too high, I put the cartridge back into the "seater" die and adjust it down a bit, and then recrimp. Then take another look. Once I'm happy with the finished product, the die maintains this dimension (OAL) quite nicely...within 0.005-0.008" or so. I don't believe that there is anything to be gained by asking for greater accuracy from one shell to the next.
Remember to relube the die occasionally, near the case mouth, with a Q-tip.
Ensure that your sizing die gives you a brass case i.d. of at least 0.006" less than bullet o.d. in order to provide sufficient case tension to prevent bullet creep with recoil. The bullet is held in the brass case primarily by neck tension, secondarily by crimp.
Make sure that your expander die does NOT act to enlarge that dimension again after you've sized the case. You may need to reduce, slightly, the o.d. of the expander button so it doesn't open up your case too much.
I don't care much about OAL as I'm looking for a finished product that has the crimp where I want it. I use a wide variety of bullet designs and most of them don't come with OAL suggestions. Any particular bullet design will be characterized by its own particular necessary OAL, by virtue of the placement of its crimping groove. There are folks that, in order to hold down OAL in a short cylinder, will crimp over the forward driving band, but I am not one of them.
I also will admit that I've never trimmed my brass, neither do I tumble my brass. I do bright-light the inside of each case and clean my primer pockets before loading. I am meticulous also, but I get to pick "where." I do chrono carefully, and have shot many 5-shot "rested" 25 yard groups of 0.6" center-to-center with .45 colt and .500 Linebaugh.
Once I have a good-looking product, I record that OAL and check successive loaded cartridges against it, and the variance is always less than 0.010".
I sincerely believe that REDDING's advice to start with the bullet higher in the case was "right on." Please keep in mind, however, that the fellow you talk to on the phone is not "necessarily" an experienced reloader. Recently, I have spoken with at least 4 or 5 die manufacturers. I had one fellow tell me that their sizer dies reduce the brass i.d. by 0.005"-0.010" less than bullet o.d. for great neck tension. I told him he was wrong, as I had TWO sizer dies from them in front of me...that only provide 0.003" of neck tension. The fellow was a nice guy, but mistaken about that important criterion.
Sonnytoo

 

[islander]

Gentlemen thanks for your replies and for sharing your knowledge. All of it is valuable to me as I this is my first reloading season. At some point I hope to be able to relax on the exactness of this hobby, once I learn where the real dangers lie.

I will post up Redding's official answer to my question once I receive it.

 

[Rick Courtright]

At some point I hope to be able to relax on the exactness of this hobby, once I learn where the real dangers lie.

Hi,

W/ apologies, this is gonna be a bit of a hijack:

In your quest for "relaxation" you'll find that reloading is one of those hobbies where there are LOTS of ways to do several of the "chores" and still produce a serviceable, satisfactory, even "close to perfect" result, much of if depending on what your NEEDS are.

On the subject of OAL, since that's a big concern of the thread, watch your manuals and take note of how they list it. Some give you a "minimum" and few list a "maximum." I like the "minimum" figures myself, because I know that way I can seat bullets further out until they "don't fit" (cylinder, magazine, chamber?) w/o problem... OTOH, if they give a "maximum" I have less of an idea what my "wiggle room" factor is.

Another thing to look at is the bullet length. Whatever OAL figure the book gives, it's developed w/ a specific bullet. One of the same weight and style from a different mfr is PROBABLY gonna be close enough in length that you need not worry about the OAL.

However, it's always a good thing to do some measuring and put the calculator to work when changing bullets. Keep notes...

If you start w/ the EXACT recipe from the book, you can set the exact OAL easily enough. A major concern w/ pressure is how much volume's available inside the case. If you use the book OAL for that bullet, subtract the nominal case length and that tells you how much of your bullet should be OUTSIDE the case.

Formula No. 1: "book" cartridge OAL - case length = exposed bullet amount

Now measure one of your "proper for the recipe" bullets for OAL. If they're a design that can easily be dinged up, like certain soft point rifle bullets, measure a few of your best ones and get an average. You've figured out how much should be outside the case, so subtract that from the bullet's OAL and that'll give you how much should be INSIDE the case. Write it down!

Formula No. 2: bullet OAL - exposed bullet amount (Formula 1) = bullet amount inside case

From here, you can figure approximate OALs when using slightly different bullets by inserting them the same amount as you calculated. (Assuming you use the same case as the recipe calls for: the volume of cases can vary by brand, so that's something for the next "class!")

Formula No. 3: "your" cartridge OAL = nominal case length + unknown bullet OAL - unknown bullet amount inside case (Formula 2)

None of this advice is "perfect" in all cases, nor carved in stone for any, so always remember, "Start low, work up!"

Rick C

 

[gmaske]

Rick
Doesn't look like a "hijack" to me! Just good words of knowledge my man. 8)