>>278709826
A lot of them have at least some sort of flaw.
Berettas and glocks don't do shit against armor and helmets.
Revolver has trashy sites and reload times, tec-9 is eh all-around, all shotguns are pretty bad beyond a small close quarters range, and even then rifles work just as well for most of the scenarios, Famas and P90 have recoil or bad sights, UMP and MP5 are just inferior rifles. Sniper rifles are fuck expensive and od fuck all outside of M99.
All rifles are pretty much flawless, AKM has the benefit of 1HKO for a very affordable price, M249 is an M4 on roids.