At my outdoor range the other day, I was on the 50' pistol/.22 rifle range. Guy two lanes down was shooting his Glock. I was apparently lost in my Mark III world when BLAM. Nearly popped an ear drum.
Looked over and he had substituted his Glock for an AR "Pistol". .223 carbine without the butt stock.
Everyone on the 50' range was shooting him daggers. He said "What?". I very politely mentioned that the range was pistol/.22 rifle. BIG ASS sign said no center fire rifle.
He said "his AR is legally considered a pistol". I politely suggested he consult with one of the range masters. He did and they moved him to the center fire rifle range.
I went down later and watched him shoot his "pistol" on the 50 yard range. Looked very uncomfortable shooting. Not very accurate in that configuration.
I like AR's but that seemed to be somewhat a waste of money. IMO.