It depends what kind of shooting you are doing? All Lake City (LC), for example, should be similar enough that you won't see an accuracy difference in service rifle match shooting except at 600 yards. As the years go by, the tooling that makes the brass wears out and is replaced, so for long range matches I do keep the year the same then sort them by weight looking for weights that have more cases hitting them than others. Those often identify a set of tools. Sort them after the blueprinting because then you are matching case powder capacity, as well, which helps at long range.

Keep in mind that the military hard brass is for withstanding loose full auto chambers. You won't subject it to that, but the harder alloy will work harden faster than soft commercial stuff, so be prepared to anneal case necks every four or five loadings. Also try to set up your sizing dies to just bump the shoulder back slightly for long range, then load them singly for that course of fire. That will help the hard brass keep from cracking at the pressure ring and letting the heads separate.

__________________
Nick

__________________________
Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Instructor
NRA Patron Member

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity." Homer Powley