Crimp

[09cs]

I'm still trying to get the hang of loading 9mm so I am still loading up a few dummy rounds. These are the two crimps, one is per the instructions that came with the die, the other is about an extra 1/4-1/2 turn than that.With the one per instruction I had major set back going from 1.15x to 1.13x to 1.11x after loading it into a mag and letting the slide go and ejecting it a couple times. So I decided to up the crimp a little. I saw a little set back with this one doing the same about 6-12 times, but am afraid it may be "too much" crimp and cause pressure problems

Not sure if you can tell by the pics, but hope you can!

[pacrat]

I'm still trying to get the hang of loading 9mm so I am still loading up a few dummy rounds. These are the two crimps, one is per the instructions that came with the die, the other is about an extra 1/4-1/2 turn than that.With the one per instruction I had major set back going from 1.15x to 1.13x to 1.11x after loading it into a mag and letting the slide go and ejecting it a couple times. So I decided to up the crimp a little. I saw a little set back with this one doing the same about 6-12 times, but am afraid it may be "too much" crimp and cause pressure problems

Not sure if you can tell by the pics, but hope you can!

Crimp will not create any pressure problems. Having bullets set back into case excessively will.

[mike.h]

If you are using the Lee factory crimp die, just follow the directions. I've had good results with both 45 acp and 9mm shooting both plated and LSWC's.

hope this helps

[09cs]

Crimp will not create any pressure problems. Having bullets set back into case excessively will.

Ok I thought having too much crimp could cause some

If you are using the Lee factory crimp die, just follow the directions. I've had good results with both 45 acp and 9mm shooting both plated and LSWC's.

hope this helps

Yes it is the lee FCD, but following the instructions it seemed to cause set back after ejecting and loading a couple times

[9mmepiphany]

Are you running them through a case gauge or just dropping into your barrel to see if they'll fit your chamber?

[HTLP]

I would be very careful firing the heavier crimped rounds since straight walled rimless cases are typically fired from barrels that headspace off of the case mouth.

[09cs]

Are you running them through a case gauge or just dropping into your barrel to see if they'll fit your chamber?

Barrel

[09cs]

A fellow cal gunner sent me a pic of about what the case mouth should measure with a good, not too much crimp

[Mot Mi]

Dont set such a heavy crimp and set back is bound to happen just dont continue to chamber them over and over. They are fine once you load them once and fire them. Excesdive crimp may hinder your accuracy unless youre crimping for magnum rounds also with slow burning powders.

[bigedp51]

A taper crimp should only be .002 to .004 smaller than the diameter of the case just below the taper crimp.

A taper crimp is for streamlining the case mouth for feeding and chambering. The actual bullet grip that holds it in place is how tight the case is after expanding the case.



Below are over exaggerated examples to show the types of crimps and are way over done.




Squeeze Play: How to Properly Crimp Ammunition

http://www.handgunsmag.com/handguns/squeeze-play-how-to-properly-crimp-ammunition/

[9mmepiphany]

I had a similar problem when I first started reloading. What makes the 9mm more subject to it is that the case is tapered, as opposed to being straight walled.

Yours may be a different problem, but this solution worked for me.

How much crimp you're applying isn't the whole problem. The other part of the problem is that you are over expanding the case mouth in the Expander Die. The bullet isn't really held by the "pinching" of the crimp. What is holding it is the neck tension of the case body.

While you feel that you are returning the case to the proper proportions when you remove the case flare by crimping, there is a certain amount of "springback" to the brass...the neck tension is loss when you over expand.

What worked for me is to use the Lyman "M" Expanding die. For the 9x19mm, you'll need the 38AP (.355"), not the 38P, which will expand the case correctly and than open the mouth, not flare, to received the bullet...this maximizes neck tension. The taper crimp you apply after seating the bullet will correctly retain it and also allow it to seat on the neck