I bought one of those back in the 80's when they first came out. It worked great on my Ruger 10/22 but I couldn't get it to work on my AR. I think the distance the AR trigger had to move was too much for the cam in the BMF. It might work with some of these aftermarket triggers we have today but I don't know. The RRA, JP, etc. were not availble back then.
I used to put a M16 bipod (the old clamp on one) on the 10/22 and shoot it prone. You could shred a pop can with 30 shots in about 2 or 3 seconds. I had a lot of fun with that thing back in those days.