While it may not be all of them - just a word of caution, a lot of the PSC ones are just the free Bergman STL's which are excellent...but they're also free,

. So unless you don't print, there's little need to go to PSC for their stuff.
https://www.thingiverse.com/thing:3553160This guy's stuff is excellent. It's chunky, i.e. they're made for 15mm printing, so you don't have to worry about microscopic gun barrels for the most part. You can find most of what you'd need there. Infantry, not too sure where to source.