@TurboNormie@poa.st Ballistics son. Also it makes for a very good 7.62x39 clone out of longer barrels.

@Tripp@poa.st @TurboNormie@poa.st Not sure about _why_ you'd want a 7.62x39 clone except for the better subsonic performance that 9mm, but it's designed to be a good version of that or the Original Formula assault rifle 7.92×33mm Kurz while fitting in the M4 ecosystem including good feeding and using standard magazines and their capacities. And as everyone else is saying, better ballistics. I see in Wikipedia that the first two listed rounds use Open Tip Match, which are legal rounds for the military to use, the open tip is not for better expansion, but because irregularities in the tiny tip matter much less than the wider base, which we can be pretty sure is a boat tail for these bullets. Another issue is that .45 bullets are 1/10th of an inch wider than 5.56 NATO etc. cartridges, .300 AAC Blackout was worked up in M4s to only require a barrel change.

@ThatWouldBeTelling@poa.st @TurboNormie@poa.st x39 AR bolts have a real bad tendency to break, as in I've lost nearly a thousand replacing the fucking things. Its more a convenience thing for me when it comes to parts and such, that and I handload so I don't have to deal with garbage commercial stuff.