Originally Posted by holeshot308
Question, what is the difference between the .223 XM-885 62 gr. steel penetrator round and the .223 SS-109 62 gr. steel penetrator round? I've got a butt load of the SS-109 green tip ammo from Lake City and just wondering what's up with the XM-885 cartridge?
Additional info: these rounds use the same bullet but the SS-109 is manufactured by Fabrique Nationale (FN) However, the SS-109 doesn't meet US MilSpec (which are tighter than FN.). The green tip is a color code to show that these rounds should not be used in older rifles (they are too hot and the older rifles won't stabilize the 62 grain bullet - they have a 1:12 twist.). However, both rounds are perfectly safe for the SR-556.