Installing a muzzle thread adapter ?

[dementlr]

I want to install a muzzle adapter on my C39 pistol to change the L14x1 threads to 5/8x24, end goal being to install an AAC 51T muzzle device. As shown in the pics, the adapter does not completely cover the original barrel threads. Do I need to use shims and a crush washer to fill the gap? It is a bit over 5.5mm wide, and there is a slight taper where the barrel meets the front sight.

 

[clandestine]

Dont do it. I would bet the threads are not true to the bore and you dont have a proper crush shoulder.

 

[dementlr]

Dont do it. I would bet the threads are not true to the bore and you dont have a proper crush shoulder.

Thanks for the feedback. Prompted me to do a little more research and abandon the idea.

 

[Gcs7th]

I have a C39 and I can confirm the threads are concentric to the bore (Atleast on my gun). I had a similar problem with my YHM QD mount and I used shims from Primary Arms http://www.primaryarms.com/pws-308-muzzle-device-alignment-set-5mdas301 After shimming it I confirmed the threads were concentric with an alignment rod. http://www.primaryarms.com/geissele-17-7-62mm-suppressor-alignment-rod-gat10-260 Once I verified everything was straight I used rocksett and double checked it before firing.