Muzzle brake alignes on muzzle not shoulder

[Denns]

Hi everybody,
I got a B&T 2 chamber brake for my AR10 today which i need to mount my B&T Rotex IIA suppressor. It does not include shims to align it with the shoulder of the barrel but smaller ones to put into the brake so it gets tightned to the end of the barrel.
(I hope this is is understandable, english is not my main language....)

Normally all muzzle devices i saw until now are aligned with the shoulder, are there any downsides when i tighten it to the end of the barrel? Would use Rocksett und about 30 ft lbs of torque.

I don't now if i should buy bigger shims to put it over the thread and align the brake with the shoulder or mount it like the manufacturer wants me to do it.

Thanks for any advices!

Greetings from europe

 

[Waorani]

FALs indexed off the bore face but they were just flash hiders/brakes and not for suppressors. If the bore face is square to your bore you should be fine but check alignment with suppressor mounted with rod or by sighting down bore before firing. Are the threads on your AR10 long enough?

 

[308pirate]

Uh, buy some washers from the hardware store to make up the gap

 

[Denns]

FALs indexed off the bore face but they were just flash hiders/brakes and not for suppressors. If the bore face is square to your bore you should be fine but check alignment with suppressor mounted with rod or by sighting down bore before firing. Are the threads on your AR10 long enough?

Yeah threads are long enough, would be no problem to align it with the shoulder of the thread. Only thing i would need are some shims to get it timed.

 

[Waorani]

I thought you said it came with smaller shims that go into brake and tighten against muzzle face?

 

[Denns]

I thought you said it came with smaller shims that go into brake and tighten against muzzle face?

Yes thats how it came but theoretically i could buy bigger shims and tighten it against the shoulder. The thread is long enough the only difference is where i put the shim to time it. If i thread it on without any shims it tightens against the shoulder but the timing is not right. (its a 2 chamber comp and the openings must be sideways, now without shims its about 1/3 turn wrong)

 

[Denns]

What i asked myself is if it makes any differences to tighten it against the front of the barrel or the shoulder but it seems that its equal as long as the barrel face is square to the bore.

 

[sam4886]

You'll want to make sure the shoulder is square just like you would with the muzzle face. Generally with decent AR barrels that's not an issue.

I have an AK I out a keymo brake on for my silencer. The threads ran right up to the front sight base so it came with shims for the inside threads of the brake. They were a giant pain in the ass to get on correctly. You have to use one of those bore alignment rods you can get for the silencers to make sure the shims don't squeeze or twist out then get shot.

JMAC has a good video on theirs. That's what I used for the keymo brake for the AK. I'd go external shims if at all possible.