 The MAC-10 and MAC-11 use suppressors to reduce muzzle climb, while other designs use a combination of burst limiters, forward hand-grips, ported barrels and muzzle brakes.Gunsite, a US firearms training facility, decided against teaching machine pistol firing when it was founded in 1976.Facility experts believed that it is "a slob's weapon, useful only by half-trained or poorly motivated troops"; they claimed that the machine pistol "hits no harder than a pistol and is no more portable than a rifle."