Another Crimping ???

11 October 2003, 05:31

Hey guys- I have been perusing the old threads on here and found a couple regarding crimping bullets in magnum cartridges. I am asking this question in reference to a Browning lever gun in 30-06 and a bolt gun in 300 H&H. Has anyone done any specific experimenting with roll crimping bullets with the attachment provided in the RCBS dies? I read one reply that stated they were so variable that it was worse than not crimping at all. I just loaded some 180 Hornadys in my 300 and crimped them, but have not shot them yet. I know that crimping is supposed to create more uniform pressure curves between rounds, thus producing tighter groups. What do you guys think?

[ 10-10-2003, 20:33: Message edited by: Wyocowboyshooter ]

11 October 2003, 06:50

Bigdaddytacp

quote:
Originally posted by Wyocowboyshooter:
Hey guys- I have been perusing the old threads on here and found a couple regarding crimping bullets in magnum cartridges. I am asking this question in reference to a Browning lever gun in 30-06 and a bolt gun in 300 H&H. Has anyone done any specific experimenting with roll crimping bullets with the attachment provided in the RCBS dies? I read one reply that stated they were so variable that it was worse than not crimping at all. I just loaded some 180 Hornadys in my 300 and crimped them, but have not shot them yet. I know that crimping is supposed to create more uniform pressure curves between rounds, thus producing tighter groups. What do you guys think?

.....With my 300H/H loads I don't crimp but did polish the die expander button/ball down to give the neck a tighter hold on the bullet......IF the brass is the same lot and fired the same number of times and trimmed to the same length then the standard crimp feature worked well for me in rifle loads....if I played with the die a little to get the crimp just the degree I wanted and then locked it down ......and I also polish the expander button in those dies also ....just not as much as some others..according to the brass and size of the expander......I haven't tried any of the Lee type crimp dies but have done the bullet seating in one step and then go back with a second step of just crimping....worked well/better with some bullets and brass....good luck and good shooting-loading!!

11 October 2003, 06:51

Pecos41

Wyo - Many years ago I used to try to put some sort of crimp on my /06 ammo and doing a Roll Crimp you can run into some noticible inconsistencies if you vary brass mfgr's and if your cases are all sorts of different lengths etc.
Was any of this worth the trouble or necessary. Not IMHO.

And certainly both the /06 & H&H have enough neck on the case to hold the bullet firmly without crimping.

Bottom line, this is a non-issue in my mind for you. Not worth your time and trouble.

The only kind of crimping I do any of these days is with Lee factory crimp dies. They are far less affected by the things that drive roll crimp dies crazy. Unfortunately they don't make them for every cartridge.

Hope some of this helps with your questions.

[ 10-10-2003, 21:53: Message edited by: Pecos45 ]

11 October 2003, 06:51

NotRicochet

I'm the guy who made that statement. The reason is that the amount of crimp is controlled by the length of the case, so very slight case-to-case variations will make very different amounts of crimp. Also, in adjusting the dies, the distance from the case holder to the die is critical. If you're making any small adjustments in the die position you're also adjusting the crimp. It's a bit tricky to get it set just right and to repeat the setting if you've taken the die out of the press. The Factory Crimp Die is a lot easier to set up and gives very repeatable results, with slight case length variations producing little effect on the crimp.

I don't own any Lee Precision stock or anything, I just like those dies.
[Big Grin]