Changing muzzle device. Do I trust concentricity?

[JohnO]

I have my first suppressor hopefully nearing the end of it's jail time, a Sandman-S.

I intend to use it on a few different rifles. I have two BCM uppers with factory installed A2 Birdcage muzzle devices. I have KeyMo muzzle devices for each. What would be the best procedure to insure concentricity in order to avoid a baffle strike?

Can a new muzzle device be threaded on and trusted? Are there gauges I can purchase? Is it appropriate to have a method to check alignment periodically?

I have a friend who ordered a Sandman-S around the same time I did. He went to a gun store where they replaced the existing muzzle devices with he new KeyMo devices. From what he told me they unthreaded the existing and installed the new without checking anything.

[jandbj]

https://www.youtube.com/watch?v=hkxf6Qr3bUw

https://www.okshooters.com/threads/d...t-rods.316835/

[JohnO]

https://www.youtube.com/watch?v=hkxf6Qr3bUw

https://www.okshooters.com/threads/d...t-rods.316835/

Thank you.

[Sanch]

How close is close enough when using one of these? Suppose the rod isn't extractly center, it's skewed to the side a bit, but doesn't touch the side? Should that be okay?

[Skinner Precision, LLC]

I have my first suppressor hopefully nearing the end of it's jail time, a Sandman-S.


Can a new muzzle device be threaded on and trusted? Are there gauges I can purchase? Is it appropriate to have a method to check alignment periodically?

The most basic check assuming its a bolt or gas gun that you can look down (aka not a lever gun, m14,etc.) Is to simply look down the bore with mount and can on and look for no "shadowing" , same principle as all the old school pictures of craftsmen straightening barrels in the "old days" in various arsenals and factories.

Various companies make "range rods" or suppressor alignment rods. Drill rod from industrial supply houses can also be used.

When mounting a suppressor, the perpendicularity of the shoulder of the barrel tennon can be as important as thread concentricity. Definitely confirm that the shoulder isn't dirty/buggered up when installing the device and make sure no one does anything boneheaded like leave a crush washer in place. I once had a customer I spun up a nice custom PCC barrel from a blank get his new can in and complain about how it performed (drastic shift in impact), it originally had a muzzlebrake. Had him bring everything to the shop and I showed him his baffle strikes and took off the crush washer and then turned a peice of drill rod in a lathe to accept a chamber reamer pilot (bushing) as I didn't have a 9mm suppressor aalignment rod and showed him the difference a nicely machined shoulder made from the crush washer...

As far as checking "periodically" if its concentric it won't loose concentricity, it might however depending upon the mount type and /or if it is direct thread, have the suppressor become "loose" from the mount, at which point bad things can happen, just don't burn yourself on a hot suppressor.....

[Skinner Precision, LLC]

How close is close enough when using one of these? Suppose the rod isn't extractly center, it's skewed to the side a bit, but doesn't touch the side? Should that be okay?

Kinda depends, unfortunately, can OAL and exit bore aperture diameter both play in to the answer. Some rimfire manufacturers have a .25-.26ish apperature while some commercial 22 centerfire cans have an exit that is bigger thann.30 cal...

Most rifle builders have a clearance they want to see on a brake when they install and .020 is probably less common than .040 if you surveyed some builders. Note a brake is much shorter than a can and the longer away from the muzzle, the worse the error becomes