A 5.56 AR pistol is an AR-15 built on a pistol receiver: a short barrel, no shoulder stock, and a pistol tube or brace at the rear. Same 5.56 NATO cartridge, same magazines, same controls as a full size AR-15, in roughly half the length. The ACI-15 Micro 5 runs a 5 inch barrel and a 4 inch M-LOK rail, which is about as small as the platform goes and still works.

A lot, and anyone selling you a 5 inch 5.56 without telling you that is not being straight with you. 5.56 NATO was built around a 20 inch barrel. In 5 inches the powder does not finish burning, and you give up several hundred feet per second against a 16 inch rifle. What you buy with that trade is size, and inside a house, a hallway, or a vehicle, size wins. If what you actually want is short and hard hitting, buy the 300 Blackout version of this same pistol instead. That cartridge was designed for barrels this short. We would rather sell you the right one.

Probably not, and we will tell you that on the phone. If you are buying one AR and it has to do everything, buy a 16 inch rifle. A 5 inch pistol is a specialist: a house gun, a truck gun, a pack gun. It is an excellent second AR and a frustrating only AR.

Yes, with a caveat almost nobody puts in writing. A 5 inch 5.56 barrel is loud and it throws a large fireball. Fired indoors without hearing protection it is punishing, and that is true of every 5.56 pistol on the market, not just ours. It is still an outstanding home defense gun: short enough to work in tight spaces, accurate, low recoiling, runs standard AR-15 magazines, and takes a light without modification. The muzzle is threaded 1/2×28, so a suppressor or a linear comp will move the blast forward and away from you if it bothers you. Most people who shoot one indoors decide it should.

It ships as a complete firearm: barrel installed and headspaced, micro length gas system set, 4 inch M-LOK free float rail, M16 profile bolt carrier group, charging handle, mil-spec lower parts kit, and a 30 round magazine. The pistol tube version ships with a pistol buffer tube assembly instead of a brace, on purpose. It exists so you can fit the brace you actually want instead of paying for one you plan to throw in a drawer.

The current price is on this page and it moves with our sale cycle, but our complete pistols live in the $500 to $700 band. We are not the cheapest 5.56 pistol you can buy and we are not trying to be. What you get at this price is a firearm assembled, headspaced, test fired, and inspected in Winter Garden, Florida by the company that warranties it for life.

Yes. This is a standard AR-15 in 5.56 NATO, not a proprietary design. Standard magazines, standard optics, standard controls, standard triggers. Nothing about this build asks you to buy into a new system, which is exactly why it works as a second gun.

Yes, and this is where the gun gets good. The muzzle is threaded 1/2×28, the standard pitch for 5.56 muzzle devices and suppressors. A short barrel plus a can is the configuration most owners of this pistol end up running, because it fixes the one real complaint about a 5 inch 5.56: the blast.