After writing my last post, I found an updated version of the MIL-spec.

http://quicksearch.dla.mil/Transient/74410E9F151846288451A5048FF039AF.pdf

http://quicksearch.dla.mil/Analyse/ImageRedirector.aspx?token=251894.31482

"MIL-C-63989C (AR)
AMENDMENT 4
30 January 2001
SUPERSEDING
AMENDMENT 3
15 October 1999"

Paragraph 3.7 is changed as follows, which increases the maximum average pressure to 58,700 PSI. This is neither the SAAMI .223 spec nor the NATO spec.

"3.7 Delete in its entirety and substitute the following:
3.7 Chamber pressure. The average chamber pressure of the sample cartridges, conditioned at 70 degrees plus or minus 2 degrees F, shall not exceed 58,700 psi. Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall not exceed 64,700 psi."

Last edited by Coyote_Hunter; 02/27/17.
Coyote Hunter - NRA Patriot Life, NRA Whittington Center Life, GOA, DAD - and I VOTE!

No, I'm not a Ruger bigot - just an unabashed fan of their revolvers, M77's and #1's.

A good .30-06 is a 99% solution.