Got one. I put it on my M16A1 and it worked quite well......for about 80 rounds before it jammed. It works really well on semi but I think the full auto may run it a little too fast. I've heard others have used it FS and it worked better than mine. Might be the ammo too. I was using Winchester bulk box ammo, and I was told it ran better on CCI Blazer or Minimag ammo. Got to get some of that to try.
But it was FUN! We ran about 1,000 rounds before we got tired of clearing jams.
Lakeside makes an outstanding product, very well made.
CCI Ammo for LR guns is probaly your best ammo you can get for a reasonable price. I have a couple of 22 mags and the winchester ammo winds up all over the paper. With CCI it just makes nice groups and suprising for a rimfire to do that.