I was reading this:
and he used a -014 O-ring on the front lug to cure wiggling in his Bushy.
Anyone else do this with positive or negative results?
I had a SP1 and a CDNN large hole upper that was a bit wobbly, and the small o ring helped lots. Buy about 20 of them, as you need to change them out every other shooting session.
It's the cheap solution, you might try a Accu-Wedge for something more permanent and not expensive at all, $3-5.