I am actively attempting to complete the fully upgrade 100 guns achievement, (82 at present).

I have lists of all the weapons, and theyre completion.

AR's = 24
DMR's = 11
Handguns = 13
LMG's = 8
SMG's = 13
Sniper Rifles = 7
Shotgun's = 6

I dont get why so many AR's and so few others.