They aren't very useful, range and accuracy are compromised for the short length. You'd be better off with an MP-5 or other SMG design over an M16 pistol.
I put one together for a guy about a year ago. Had an Olympic Arms matching flat top upper and lower. Put on a Hogue pistol grip. Front end had a "customized" 8 inch barrel. What that really means is that we chopped down a full size 16" G I Barrel that the guy had, per his request, and attached a Yankee Hill Machine muzzle break. Got a YHM front end, a full floated tube design that was, I think, about 5" long. Drilled the front end and attached a flip up, fold down front site, the back was the same, but it attached to the flat top rail. We got a special piece that went between the lower and the buffer tube assembly, like the alignment washer on a stock assembly - but smaller, that gave him a single point of contact for a sling. All in all, it was okay - nothing special. Guy probably spent more money than he got fun or accuracy out of it, but to each his own.... JD
I work with a guy who used to have one, he sold it last year because after firing a mag it would jam up really bad. I could ask him and get back to you later. Personally I would just buy a handgun.
Rocky Mountain Arms made the original factory production 223 pistol. Had a 7" match barrel and would shoot under 2 inches @ 100 yards. Many AR pistol kits of today use hodge podge parts and untuned gas system causing reliability issues. Biggest problem is 223 ammo needs about 10-14 inches to burn powder. Also if one handed or limp wristed.slows bolt carrier function causing FTE or FTF. Fun but not real practicle...better register as an SBR w/m-4 or reg stock and a 8 to 10" barrel for a tactical entry weapon.
A friend of mine has the Bushmaster... It has a buffer tube, but no stock; legal reasons. But, you can transfer the uppers... So You could have a collapsable stock w/ one; however I would not recommend doing so since it may be illegal in some states without a permit. DPMS has the Kitty Kat, but it's for LEOs and Speciial Ops, etc only.
