I've got a Bushnell 1-4x on one of my .22s (pic below). It would be fine for recreational use on an AR, and tons of folks do.



However, If the gun is designated for self defense or duty I would look elsewhere. And generally, that goes for all magnified optics under under $500 that come to mind. I'm sure there will be some moans and groans among the readership over that broad statement... that's my general view of it. A Leupold VX•R Patrol 1.25-4x20mm might be worthy of consideration.