WOW AR 15 i NEED this!

May just have to pick one of these up.

My local shop has em.

I've got one, they're fun, but definitely not the same shooting experience of a genuine MG. Similar (at least as mag dumps are concerned), but certainly not the same.

That said, $300 for a bump stock is better than $12k for an M16 if all you want to do is mag dumps every now and again.

I've run mine on a .223 upper and a 9mm upper. Both ran great. The .223 runs faster than the 9mm, however that will change depending on the ammo used.

I haven't had a chance to try it with the 6.5 Grendel or the .458 SOCOM yet. The SOCOM will be a hoot for sure, but I need to load up ammo first (and, with a MWG 90-rd mag the SOCOM would be a TON of fun --~35rds of 400gr goodness!)