Trimming rifle brass shorter than spec..

impactco · April 1, 2010, 11:05 PM

I have tried RCBS X-Dies with some success. The X-Die instructions call for trimming .010" less than standard trim length. Just for fun, I have tried trimming .308 brass for my 1919A4 to this length and not using the X-Dies. I am up to 5 reloads and the brass has not stretched sufficiently to require another trim, even when using standard dies.

Is there any down side to doing this with brass for my .308 AR since I prefer to use competition dies instead of the X-Dies?

Thanks!

Shoney · April 2, 2010, 02:39 AM

It's kind of a tradeoff. The competition dies will usually give better accracy, especially at longer ranges, but the brass will stretch just above the web. Eventually, cases stretch to the point where the brass is in danger of case separation. When excessive stretch is detected, you must discard them.

The advantage of the x-dies is their design doesn't promote the stretching at the web and the brass lasts longer.

April 1, 2010, 11:05 PM	#1
impactco Senior Member Join Date: January 12, 2008 Posts: 102	Trimming rifle brass shorter than spec.. I have tried RCBS X-Dies with some success. The X-Die instructions call for trimming .010" less than standard trim length. Just for fun, I have tried trimming .308 brass for my 1919A4 to this length and not using the X-Dies. I am up to 5 reloads and the brass has not stretched sufficiently to require another trim, even when using standard dies. Is there any down side to doing this with brass for my .308 AR since I prefer to use competition dies instead of the X-Dies? Thanks!

April 2, 2010, 02:39 AM	#2
Shoney Senior Member Join Date: February 21, 2002 Location: Transplanted from Montana Posts: 2,311	It's kind of a tradeoff. The competition dies will usually give better accracy, especially at longer ranges, but the brass will stretch just above the web. Eventually, cases stretch to the point where the brass is in danger of case separation. When excessive stretch is detected, you must discard them. The advantage of the x-dies is their design doesn't promote the stretching at the web and the brass lasts longer.