Am I using too much crimp?

[blazerking78]

The title says it all. If I am how much is needed on an auto pistol. I've read the crimping thread, but I just wanted to have my work double checked by those of you with a lot more experience then I have. The bullet on the left was pulled after I got the dies set up and the other is new.

 

[rcmodel]

Yep! Too much.
It appears from the bullet photo that the crimped one has had the jacket compressed making the bullet wasp-wasted.

A proper taper crimp has the brass just kissing the bullet but not compressing into it.

rc

 

[blazerking78]

Thanks RC. Will this much crimp lead to over pressure? Should the bullet not have any marks one it has been cripmed?

 

[Walkalong]

Yep, way too much crimp.

Example of .45 ACP Crimp. 40 should be the same. Like rcmodel said, just enough to remove the bell, maybe a hair more.

Pic link

 

[rcmodel]

Should the bullet not have any marks one it has been cripmed?

Zactly!

I said:

A proper taper crimp has the brass just kissing the bullet but not compressing into it.

Your excess crimp will not cause any pressure problems, unless the "loose" too tight crimp lets the bullet compress into the case during feeding.

What?
Compressing the bullet with the crimp may actually lead to a looser bullet fit then you had from neck tension alone.

The soft lead core of the bullet has no "spring-back" like the harder brass case.
SO, when the round comes out of the crimp die, the case springs back a little, but the soft bullet doesn't.
Thats why no amount of taper crimp can make up for insuficient neck tension to start with.

Your damaged bullets may not be as accurate though.

rc

 

[The Bushmaster]

Over pressure? Probably not. .45 ACP is a relative low pressure round in the first place...I AM assuming that is a .45 ACP...

 

[Walkalong]

Looks like a 4 tay to me.

 

[blazerking78]

Yes it is a 45. Fooortayyy is for wappers. I reset my die and came up with this. Let me know what you think.

 

[rcmodel]

It looks more better but it's hard to tell from photo's.

Lay a steel rule, or the edge of your dial caliper against the case and see if there is any daylight showing where the bell used to be.

All you want to accomplish with the taper crimp is to remove the bell and make the case wall perfectly straight again.

rc

 

[The Bushmaster]

Looks good to me...Don't know about the other two "critics" on here, but......

 

[ants]

Just a tiny interjection:

Depending upon the type of crimp die you use, case length affects the amount of crimp.

Even though I don't trim auto pistol brass, I certainly trim 357 and 44 mag so I get the consistent revolver crimp I need.

Anthony

 

[blazerking78]

I realy appriciate all the help from every one.

 

[Drail]

Before you load a round hold an empty case up to a good light source and sight down the side of the case. Can you see the flare of the mouth? Now load and crimp a round until you can't see any flare looking down the side of the case. Then crimp just a little more. I mean just a little bit more. That's all you really want to do a semi auto round, just remove the flare because the round has to stop in the chamber on the mouth.

 

[xmanpike]

after viewing this i think i may have been over crimping my bullets. is there any danger to this or just a possible loss of accuracy?

 

[The Bushmaster]

If you do crimp them tooo much you stand a chance of the cartridge going too deep into the chamber and out of reach of the firing pin...

 

[Walkalong]

The second crimp looks very good. I was fooled on the first pic. It looked longer for some reason.

 

[ants]

Well yes, Anthony, when a 45 caliber looks like 40 caliber, I believe that the crimp is a bit too tight! Don't you?

 

[FROGO207]

Is that a one size fits all bullet? I gotta get me some of them.

 

[lindy]

if you take a look at the base of the case in the second pic, it appears there is some damage to the rim------ Be Carefull..

 

[tlen]

Generally .45ACP should be crimped in the range .469-.471".

 

[blazerking78]

The damage to the case head has been discussed in a different thread. My newest 1911 didn't have all of the proper machining done to the breach face. A very small part on the edge is raised and causing the casing to dent. Its no biggie, I have ordered files to correct the problem. Its small enough that it would not be worth it to me to send it in to Taurus.

I miked all my cases in the test batch and they are all at .470 to .471.

I have to say that I love my RCBS bullet puller. I would waste alot of brass and bullets trying to get every thing correct.

 

[David E]

Run a few thru the loading cycle of the gun and see if the bullet is pushed back into the case.

THAT can cause serious over pressure problems far worse than a little too much crimp.

I don't care if I indent the pistol bullet with the crimp as long as the bullet does not set back into the case during the trip up the feedramp.

Safety first.

 

[Walkalong]

when a 45 caliber looks like 40 caliber, I believe that the crimp is a bit too tight!

I knew someone would say that.

A very small part on the edge is raised and causing the casing to dent

It should not cause that dent, it should only stamp a small, very shallow (.005ish) indention in the case.

 

[Steve C]

The purpose of the crimp is to hold the bullet and prevent set back during feeding, any more than needed to perform these functions may be considered excessive.

The proof however, is in the shooting not in how it looks or what they measure. If they shoot well who cares how much the crimp is?

 

[Walkalong]

As long as it doesn't adversely affect function, and shoots well, it doesn't matter, much.