Attaching an M*Carbo muzzle brake to a Ruger PC9

I have introduced myself previously but I have a question about attaching an M*Carbo muzzle brake to a Ruger PC9 and not sure where to post. I have watched a couple of videos and one mentioned using shims to time the brake, which is fine but where does one get shims? I live in Canada. Thanks for any help.


@Osprey a crush washer works well, shims can be made from sheet steel. Also, a peel washer that is made of layers of metal stamped together in a stack works well. Unless you attempt to order one of these things from Colt or S&W you should not run afoul of the ITaR statutes. Washers are washers, nothing dirty about ‘em. You may find a hardware store that sells black coated thin washers of that size. Or maybe an automotive supply store. I have even found beautiful nitrided washers at big lumber yards here in the lower 48.


Thanks, in Canada that is probably the easiest to shop locally but I live in a smaller town about 6 or 7 hours away from decent shopping. I will see what I can find or just try it with the crush washer. This is the first gun I’ve owned that you can do something with so it is a learning process.
Thanks again.


Turn it slowly as you reach the point you want to stop at with the crush washer. I sometimes use a drop of castor oil to lube the threads. Works like a low stick thread locker and makes the process smooth.


Thanks, is there a particular reason for castor oil?


Castor oil starts out slick, but when heated up, it gets sticky, and at some point like varnish. The opposite of most thread locking compounds. Rockset works the same way but sets up really hard and is also sometimes hard to find. I like the ability to remove the part but not wondering if it will fall off.


Hi Mic, thanks for the info. I will have to buy some.


Great low tack thread locker. My favorite for muzzle devices.