Having issues with shims for timing mds. Help plz :)

[Len5E1]

Hey there. So I don’t know what I’m doing wrong all of a sudden. I’ve timed several muzzle devices in the past for my suppressors and never recal having any problems but lately I feel like it’s always a problem. So what’s happening is the shims are smashing easily and either bending over each other or into the muzzle device a bit. Here’s the two examples:

1) Keymo devices. These seem to have a slight taper near the threads which makes less of a face for the shims to contact. So when I try to torque to spec the shims will actually bend into this taper area and get ruined.

2) I just tried timing 5/8x24 Surefire md using the shims it came with. The Surefire also has a sort of thin face to it where it contacts the shims but no taper so it’s not as bad but when I tried timing it to get it to spec the shims bent right over each other. Part of this I think is because while torquing it’s impossible to keep multiple shims perfectly centered up, they like to sit off center. I feel if I only had to use 1 shim it would be ok but my Surefire devices are horribly timed with my criterion barrel and requires 3/4 turn to get to 12 o’clock which is several shims.

I have accuwashers coming today which I hope will solve my problems but I still want some feedback as it was very frustrating feeling like an idiot not able to time some basic muzzle devices without shims getting ruined as soon as I pass 25 ft. Lbs.

 

[Gasgun]

I find that putting the barrel in a vertical orientation when installing the SureFire MD helps keep the shims lined up and prevents bending them.

No experience with Keymo.

 

[msgriff]

Look at the shoulder of the muzzle threads to see if it has a relief or undercut ("C" in the image below). If not, you may have to use a beveled or chamfered spacer. Accu-Washers may work but you might have to chamfer them yourself.

 

[hlee]

Yeah, get a set of accuwashers.