theses bushings suck....
like wtf the keep moving and are impossible to shim with
seriously get systema area 1000 bushings, they are the best 6mm solid bushings.
able to completly shim prefectly by gearbox.
Like the last guy said they don't fit in the hole all that well, except I had to make the holes bigger on my gun. I used a tactic i read on another guys review of some bushings. Use some scissors and scrape out the sides of the holes.
They do their job as shims, the only thing that I noticed was that they do not stay in the holes of the gearbox all that well. a few of them snap into place very well while the others are barely held in there.