ATI Alpha Maxx 5.56 NATO 7.5" 60rd Pistol

The Alpha Maxx is a large format 5.56 pistol built on a 7.5" barrel. A 7" M-LOK handguard covers most of that barrel with flip up sights riding on top, and a brace at the rear gives a stable point of contact. The pistol grip is a standard A2, so any AR grip swaps straight in. The receiver set is polymer, which is where the weight savings come from, and the fire control group, buffer system and magazine well are all AR-15 pattern, so parts and accessories are easy to find.

The headline is the magazine. This one comes with a 60 round mag, which covers most of a range session between reloads and makes the gun a novelty in the best sense. Be realistic about what a 7.5" 5.56 barrel does: velocity drops hard compared to a carbine, muzzle blast is loud, and flash at the muzzle is significant without a device to tame it. Inside a house or across a range bay none of that matters much, and the payoff is a 5.56 host short enough to store in places a carbine will not fit. The muzzle is threaded, so a brake or a can can go on later. Flip up sights come installed, and the M-LOK slots handle a light.