Well you have to use their guns and their ammo....well you don't have to but don't get caught. I wasn't lucky enough to be in SF, Ranger, or infantry so I got stuck with a basic M-16, a basic M-9 and what ever else I could scrounge. Some of the guys put Crimson Trace grips on their pistols. I figured I would be using my M-16 more so I bought my own Red dot. Then a bunch of other guys did as well. No issues with us doing it. Again we were using our issued M-16s and M-9 and their bullets so no big deal. Other than that you could pretty much set up your stuff anyway you wanted. I has a double frag grenade pouch, single smoke grenade pouch, 3 double m-16 mag pouches, a single m-16 mag pouch and a knife on my body armor.