crimping

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the fatman

Single-Sixer
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Mar 23, 2009
Messages
325
I put a pretty heavy roll crimp on my 44s and 45s. Question is can you have a too heavy of a crimp?
 

The Preacher

Single-Sixer
Joined
Mar 24, 2002
Messages
391
fatman, I'd say yes as you can put a too heavy crimp on that'll buckle the case and then the loaded cartridge won't enter the chamber. Plus a too heavy crimp may well damage the bullet depending on the bullet. However one can put a very heavy crimp on and still be good. Flatgate is one who knows how to put on a "heavy" crimp. :)

The Preacher
 

contender

Ruger Guru
Joined
Sep 18, 2002
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20,993
Usually you have more buckling issues with bottleneck rifle cases. However, you can overdo it with pistol cases as well. It's just not as easy to buckle them due to the design of the dies.
 

Sonnytoo

Blackhawk
Joined
Aug 4, 2007
Messages
631
Thr crimp is a subjective thing and you do it by feel. By slowly increasing the crimp, you can "feel" when it's about max efficiency. Do it too much and I end up with a circumferential line around the case...about 1/4" below the crimp. Yeah, I've done that too, and it's not something you want. That's way too much. And of course, you work the brass too much.
Some well-known experts, bullet manufacturers and reloading machine customer service engineers tell me that, by far, the most important thing you need is to have the case i.d. at least 0.004" smaller than the bullet o.d. One well-known fellow told me that case friction means that you almost don't need a crimp...but he was overstating the point. Another said that, by case friction alone and NO crimp, you should be able to put the loaded cartridge nose down on your desk and push on the case real hard and NOT be able to push the bullet back into the case. I have tried that with my .45 Colt and case i.d. which is 0.006" smaller than bullet o.d., and it works for me. For heavy loads, I try to use a nice roll-crimp that is just short of max: i.e. where any more crimp would distort the crimp profile.
And...for .45 Colt, if your sized i.d. is not small enough, try a .45 ACP die. Someone here (and on Smith forum) gave me that excellent advice. It's what I use.
My .44 sized brass is 0.4265" for my .430" cast bullets. That's not as much case friction as I would like, but I'm shooting mid-range loads, in .44 Special, that don't exceed 1000 fps, and so far that's fine.
You can also pick your bullet design. I have several 240gr SWC cast bullets, .430", by different manufacturers. The Keith design has a much deeper crimp groove...which just has to be a good thing in my book. And then, to go a step further, Elmer even designed his crimp groove to have a different contour than some other folks. I believe that the top edge of his crimp groove is squared off at the top; some bullets have crimp grooves than are slanted both top and bottom of the crimp groove.
Good luck.
 

bearing01

Bearcat
Joined
Sep 15, 2009
Messages
71
Question:

For handgun rounds, can you avoid the crimp all together? I'm looking at the Lee Turret press and it seems that the 4th crimp die is optional, since the expander die doesn't over-flare the case and the flare is eliminated in the bullet seating die stage. I would think that cases would last longer if you don't crimp them.

http://www.leeprecision.com/cgi/catalog ... istol.html
We use a solid carbide insert, ground to a special contour that does not leave the objectional belt mark on the case, common to ordinary carbide dies. With a carbide sizer, no case lube is needed, and you don't even have to clean your cases.

No need for a taper crimp die, plus better accuracy with Lee Dies. Taper crimp dies are used to correct the problems caused by the improper expanding plug design or adjustment. They distort the bullet shank and reduce accuracy. Because the Lee Expander flares the minimum amount, consistent with easy bullet insertion, all of the flare is removed with the bullet seating die, thus eliminating the need for a taper crimp die.
 

slippingaway

Blackhawk
Joined
Oct 19, 2007
Messages
525
bearing01":3gyyisum said:
Question:

For handgun rounds, can you avoid the crimp all together? I'm looking at the Lee Turret press and it seems that the 4th crimp die is optional, since the expander die doesn't over-flare the case and the flare is eliminated in the bullet seating die stage. I would think that cases would last longer if you don't crimp them.

http://www.leeprecision.com/cgi/catalog ... istol.html
We use a solid carbide insert, ground to a special contour that does not leave the objectional belt mark on the case, common to ordinary carbide dies. With a carbide sizer, no case lube is needed, and you don't even have to clean your cases.

No need for a taper crimp die, plus better accuracy with Lee Dies. Taper crimp dies are used to correct the problems caused by the improper expanding plug design or adjustment. They distort the bullet shank and reduce accuracy. Because the Lee Expander flares the minimum amount, consistent with easy bullet insertion, all of the flare is removed with the bullet seating die, thus eliminating the need for a taper crimp die.

Lee's 4th die is a factory crimp die, and you're right, it's optional. However, if you pass on the factory crimp die, you have to adjust the 3rd die (seating die) to crimp. Traditionally, everyone used 3 die sets, where the third die did the seating and the crimping. A lot of people now prefer to do the two in separate steps, so they adjust the seating die so that it doesn't crimp.

Either way, you need some kind of a crimp. Without it, a semi-auto may push the bullets back into the case during feeding, causing feeding problems and increased pressure in the case. Worst case scenario is a ka-boom of the gun. For revolvers, heavy recoil can cause the bullets to move out of the case, locking up the gun.
 

the fatman

Single-Sixer
Joined
Mar 23, 2009
Messages
325
:D Thanks gentlemen. I'd forgotten the bullet test. I used to check my semi auto rounds that way. And I see that my bullets accually expand the case some what. I think I need to back my crimp off and just do a more gentle one just to make it look better. I tend to fall victim to the old adage if a little does a little good a lot does a lot of good. :shock: Kind of always liked toolman Tim. :lol:
 

Rick Courtright

Hawkeye
Joined
Mar 10, 2002
Messages
7,782
the fatman":an9q85c9 said:
I put a pretty heavy roll crimp on my 44s and 45s. Question is can you have a too heavy of a crimp?

Hi,

I 'spose it's "possible" but I don't know how "probable?"

The buckling issue's already been mentioned, but I'm thinking back to something Weshoot2 posted maybe a couple of years ago. As most of us know, he loads a LOT of pistol ammo, and does more than a fair amount of testing doing it...

The post I'm thinking of talked about "working up" the crimp and watching the overall performance of the round (accuracy, velocity, consistency all combined) improve "to a point." Memory's fuzzy whether it reached a plateau and stayed there, or started to drop off.

Anyway, the gist of the story was there IS an optimal amount of crimp you'll have to determine thru your own testing. Whether there's "too much" you'll have to determine on your own, I guess. I'd suggest a "use enough but not more" approach, if for no other reason, than to maximize brass life.

Rick C
 

Sonnytoo

Blackhawk
Joined
Aug 4, 2007
Messages
631
the fatman":21o13a3s said:
Question is can you have a too heavy of a crimp?

This is a decent roll crimp, IMHO.

PA030012-1.jpg


This one is way overdone. Note the circumferential line below the actual crimp.

PA030011-1.jpg


A crimp is an addition to, but not a substitute for the friction fit of a nicely-undersized case. Notice that the case mouth is now starting to flare out...just the opposite of what is needed.
Sonnytoo
 

edlmann

Blackhawk
Joined
Apr 6, 2009
Messages
785
the fatman":1cucmlmn said:
I put a pretty heavy roll crimp on my 44s and 45s. Question is can you have a too heavy of a crimp?

If nothing else, you'll wear out the brass sooner. Revolver cases usually split at the case mouth.
 

flatgate

Hawkeye
Joined
Jun 18, 2001
Messages
6,784
I crimp the crap outta my handloads except when I'm monkeying around with the fast powders.

I've not had much trouble with brass life, either, but, I figure it's an expendable commodity. 350's at 1500 fps just gotta have a firm "bullet pull" and a killer crimp... :D

JMHO,

flatgate
 

the fatman

Single-Sixer
Joined
Mar 23, 2009
Messages
325
Wow! Thanks again for all the info even pictures this is such a great bunch of folks. :D
 

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