Rethreading ASR Flash hider for AK ???

[Triggerhappy]

I have discovered that no one makes a M14-1lh flash hider for Silencerco ASR. Silencerco makes a 13.5-1lh. Is it totally wrong to think I could get a 14-1 bottoming tap and just chase the 13.5mm threads to 14mm it is less than 20 thousandths different and of course make sure it is concentric before shooting. I know that Lantac makes a brake but I don't really care for it and it is 2X the cost. I don't want to change from ASR either as I have about 2 dozen asr mounts already.

 

[346ci]

It could be done with a tap but I'd be worried about the barrel threads being concentric also. Either way you may be sending both off to be done on a lathe.

 

[DustBun]

I agree with @346ci , concentricity will be critical.

Below is the thread profiles of both overlaid in CREO. The red is the M14x1 and the blue is the M13.5x1 threads.

It may look like a lot of extra material but it is not.

D	Major Diameter	13.5
P	Pitch (Distance)	1
D2	Pitch Diameter	12.85
D1	Minor Diammeter	12.417
Hs	Thread Depth	0.541
fcs	Crest Width	0.325

D	Major Diameter	14
P	Pitch (Distance)	1
D2	Pitch Diameter	13.35
D1	Minor Diammeter	12.917
Hs	Thread Depth	0.541
fcs	Crest Width	0.325

 

[DustBun]

I should have added in the previous post that that is assuming perfect pitch timing with the existing threads. If the threads are not timed perfectly then you will not get a full thread height so I would not recommend it.

Again, the red is the M14x1 and the blue is the M13.5x1 threads. You can see how full threads will not be developed because the minor diameter of the M14 is less than the major diameter of the M13.5.

 

[Bantam1]

Why not just get a thread adaptor? I know Griffon used to make a 14-1 to 5/8-24 adaptor that was well accepted. I'm sure there are others.