40 bullet penetration (through soft cover) kills
extended mags are and attachment for your gun when you get 40 bullit penetration kills with fmj
ump is .45 while uzi is 9mm so .45 is bigger and is stronger
Extended Mags
get 30 FMJ Kills
it gives you more bullets
30 rounds = stick mags, 45-70 rounds = drum mags
30 in Standard mags 40 in Extended mags 75 in Drum mags those were the common mags, there are also custom 60 round mags that look like 2 standard ones back to back that form a half-circle shape
ACR with ACOG and heart beat sensor Scar-H FMJ Holographic
you can get extended mags with 400 kills with it
30-45.
You have to get a certain amount of kills while using FMJ (Full Metal Jacket)
It becomes available after you get 40 through the wall kills with fmj on.