357 Mag - Collet Crimp Location?

[IrishPsych]

These 357 will be semi hot rounds with 13.5gr if 2400 and with a coated 158gr rnfp bullet.

Manuals differ in OAL. Some have 1.590 and others have 1.550 or 1.570.

Bullet I'm using will need a OAL just of 1.570 in order to crimp at the crimp groove.

Photo below is 1.575 and crimped just shy of the groove. I'm also using the Lee COLLET crimp die. Not a taper crimp or roll crimp. Was suggested to use in rounds that are used for not revolver and rifle.

Does that round look good?

Should I let it out to say 1.580 and don't worry bout the crimp groove?

I can also run it a little shorter but then pressure spikes will likely happens using 2400 powder.

 

[38SPL HV]

Looks good but I prefer a moderate heavy roll crimp. I tried using Lee collet die but I found that it reduced case life since when done with a firm crimp would work the case mouth too much (those small indentations characteristic of this die will ultimately fail in my experience).

I use Redding Profile or Lee FCD on my magnum level loads when crimping in crimp groove, Lee taper crimp when crimping on the bullet (and yes, bullets in magnum level loads will stay put (not move) with the taper crimp even in my Ruger SP101).

By the way, your 13.5 grs/2400 with 158 gr cast bullet is an excellent load...it's velocity exceeds Rem/Win/Fed 158 gr JSP 357 Magnum factory loads with the added benefit of being hard cast with better penetrative capabilities on game.

 

[muddocktor]

Crimp it in the crimp groove; the pressure differential will be inconsequential and to do it right you should work up to your max load anyways, by testing and observation. That's why they put the crimp grooves in bullets meant for 357 anyways. And I'm also one to use a good roll crimp as I find it does better and has less ES and SD with a firm roll crimp. All your slower "magnum" powders do better with a good firm roll crimp in my experience with 357.

 

[Nevada Ed]

That bullet has a very fine/small crimp area.......... (Cast Performance ? )

looks to me, like you need to seat that bullet just a little bit more to hit the crimp area of that bullet.

Most of my lead bullets have a crimp area at least the width of a penny, or more.

It does not hurt if you don't use the crimp indentation but it does make the crimping job easier, if the case can use it.

Have fun.

 

[BLUEDOT37]

I can also run it a little shorter but then pressure spikes will likely happens using 2400 powder.

Welcome to the forum!

Not sure what you mean by this? You're well under max & a few thousands won't make a difference here. 2400 is very forgiving.

Ditto the moderate/heavy roll crimp in the middle of the crimp groove, especially when using a slow powder.

And you only need regular primers with 2400 (Speer/Alliant manual).

Note the COAL" in your records but disregard what other bullet's COAL" measure to as long as yours chambers properly in your revolver when seated to the cannelure/crimp groove.

Did you work up to this load? Always best to & avoid surprises.

.

 

[Maurice H]

As others noted, seat your bullet to a depth that puts the mouth just shy of the top of the crimp groove and apply a solid roll crimp, which is important for two reasons; prevent creep and ensure proper ignition/pressure.

 

[mikld]

A few decades ago when I reloaded my first revolver round ('69) I figgered the bullet designers knew where to place the crimp groove. Did some research and the most common answer was "seat to the crimp groove and roll crimp, and fergit book OAL". And this was waaaay pre-web...

 

[Nevada Ed]

A good/proper crimp needs two main things to happen.

#1
all the cases should be the SAME over all length.

#2
the bullet is seated into the case the correct amount.

Hopefully you have quality bullets with the cannelure in the same area of all bullets.....

and your die is tight without any movement and you use a "Full stroke" each time, for the operation....

anything else is nit picking.

 

[wv109323]

It would be best to use the crimp groove and roll crimp into it. This with keep the bullet from moving under recoil. The hotter you load the more apt they are to move under recoil.
Your max. load wiil somewhat depend on seating depth. Load a few under your desired load to make sure there is not a pressure problem.
The crimp groove was located so that the bullet would fit into all applications.