Plated bullets cracking......

[Furncliff]

I'm researching the use of plated (115gr RN) bullets in 9mm and came across a statement about crimping too tight and causing the plating to crack and putting yer accuracy in der terlit.

Is this an issue, can you see the cracking?

Crimp question #2:Switching separate crimp die from from FMJ to lead should there be a major change in crimp required?

 

[rcmodel]

1. Yes. Too much taper-crimp is bad.
But too much crimp on any bullet is bad.

2. No.

No taper-crimp adjustment should be necessary.
9mm should be taper-crimped so the case mouth measures .376" when completed.

All taper crimp does, or is supposed to do, is close up the case mouth bell to a straight case again.

It does little or nothing to hold the bullet in place.
Proper case neck tension is what holds the bullet in place, and excessive crimp can mash the bullet smaller and ruin the case neck tension you started with.

rc

 

[tightgroup tiger]

Something else I do ( and many other plated bullet users) is chamfer the mouth my 9mm cases when using plated bullets.
That helps a lot with not cutting the plating when crimping the loaded rounds.

A wire edge inside the case will cut into the plating even if the crimp die is set up perfectly. When setting up my crimp die after chamfered the cases, I will load a dummy then knock the bullet back out with my kinetic bullet puller to see if there is line around where the mouth was crimped, then adjust my crimp die accordingly.

 

[243winxb]

Plated Bullets Link

Interesting thread on plated with photos. http://thefiringline.com/forums/showthread.php?t=494465

 

[PO2Hammer]

9mm shouldn't require any crimp, so there should be no need to worry about cutting into the plating.
Even with the .357 you shouldn't need that much crimp.
I've loaded thousands of them in 9mm, 40, 10mm, 45acp, .38 spl, 357, 45 Colt and never once 'cracked' the plating.

 

[Walkalong]

Since all you are doing is removing the bell or a hair more when taper "crimping" 9MM rounds, there should be minimal to no adjustment for the crimp going from jacketed to lead or plated. 1/8 turn or so, if your picky about taper crimps.

And that means you are in no danger of pushing the case mouth far enough into the bullet to tear or "crack" the plating.

Here is a bullet I pulled form a .400 Corbon after a roll crimp. I backed off from this setting, but even with this crimp there was no sign of tearing etc in the plating. If it can take this roll crimp, there is no way a proper taper crimp is going to damage it.

Pick up some of theses Berrys 115 Gr HBRN-TP bullets and run them as hard as you want in 9MM.