Trifecta mount question!

allen16323 · 09-21-2016, 05:08 PM

The specwar Trifecta mounts, was wondering if they index or torque to the muzzle or to the barrel shoulder? I have a threaded barrel that the threads are concentric but are cut way long in the tooth. I ask because I have a few options it it indexes/torques to the shoulder I can have the break bored out and taped, hoping it is in the shoulder. Cannot really cut the muzzle back because I am right on the end of 26" oal rule and don't want to SBR it but could always pin and weld the brake.

Thanks in advance for info.

Allen

wtrski76 · 09-21-2016, 05:50 PM

They index on the shoulder. The Silencerco thread spec shows .600 +/-.010" from the shoulder to the muzzle, with a .600 min OD at the shoulder. The threads are a bit deeper than that on the muzzle device, but not sure without putting a caliper to it. If they are too long, you can always get a thread spacer that they sell to use for use on .22 cans with short threads when using them on rifles with long threads like this one:
http://www.silencershop.com/accessor...er-1-2x28.html

areekalaan · 09-21-2016, 05:51 PM

silencerco uses washer type shims for timing brakes, so I would say they tighten to the shoulder. You just need a precision cut washer / spacer to fill the gap.

allen16323 · 09-21-2016, 06:10 PM

Thought it was the shoulder, so boring the brake out is probably the best option. Don't know about a spacer because tolerance stacking could be an issue would it not? Been so long since I worked in the mechanical end of drafting I can't remember, guess I worked in the construction end too long.

wtrski76 · 09-21-2016, 06:15 PM

If you just need one of the spacers and a timing shim or two, I wouldn't worry about tolerance stacking - they are made for this specific purpose Now, if you need 3 or 4 spacers, that may be a different story. How long are your threads?

allen16323 · 09-21-2016, 06:28 PM

Quote:

Originally Posted by wtrski76

If you just need one of the spacers and a timing shim or two, I wouldn't worry about tolerance stacking - they are made for this specific purpose Now, if you need 3 or 4 spacers, that may be a different story. How long are your threads?

Will measure for sure when I return home. Am in town gathering parts for a DIY ss tumbler at the moment.

DethRokRyan · 09-22-2016, 04:59 PM

If that brake has a nitride finish (and I think the Trifecta brakes do), boring it out is gonna be difficult.

09-21-2016, 05:08 PM	#1
allen16323 Senior Member Join Date: Mar 2011 Posts: 550 Rep Power: 6	Trifecta mount question! The specwar Trifecta mounts, was wondering if they index or torque to the muzzle or to the barrel shoulder? I have a threaded barrel that the threads are concentric but are cut way long in the tooth. I ask because I have a few options it it indexes/torques to the shoulder I can have the break bored out and taped, hoping it is in the shoulder. Cannot really cut the muzzle back because I am right on the end of 26" oal rule and don't want to SBR it but could always pin and weld the brake. Thanks in advance for info. Allen __________________ In a zombie apocalypse Washington DC is the safest place to be, nobody's got any brains to attract them.

09-21-2016, 05:50 PM	#2
wtrski76 Senior Member Join Date: Feb 2013 Location: Lone Star State Posts: 110 Rep Power: 5	They index on the shoulder. The Silencerco thread spec shows .600 +/-.010" from the shoulder to the muzzle, with a .600 min OD at the shoulder. The threads are a bit deeper than that on the muzzle device, but not sure without putting a caliper to it. If they are too long, you can always get a thread spacer that they sell to use for use on .22 cans with short threads when using them on rifles with long threads like this one: http://www.silencershop.com/accessor...er-1-2x28.html Last edited by wtrski76; 09-21-2016 at 05:53 PM.

09-21-2016, 06:10 PM	#4
allen16323 Senior Member Join Date: Mar 2011 Posts: 550 Rep Power: 6	Thought it was the shoulder, so boring the brake out is probably the best option. Don't know about a spacer because tolerance stacking could be an issue would it not? Been so long since I worked in the mechanical end of drafting I can't remember, guess I worked in the construction end too long. __________________ In a zombie apocalypse Washington DC is the safest place to be, nobody's got any brains to attract them.

09-22-2016, 04:59 PM	#7
DethRokRyan Senior Member Join Date: Sep 2010 Posts: 2,768 Rep Power: 19	If that brake has a nitride finish (and I think the Trifecta brakes do), boring it out is gonna be difficult. __________________ The core principle of freedom is the only notion to obey.

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09-21-2016, 05:51 PM	#3
areekalaan Expert Wannabe Join Date: Jul 2014 Location: NW PA Posts: 4,270 Rep Power: 35	silencerco uses washer type shims for timing brakes, so I would say they tighten to the shoulder. You just need a precision cut washer / spacer to fill the gap.

09-21-2016, 06:15 PM	#5
wtrski76 Senior Member Join Date: Feb 2013 Location: Lone Star State Posts: 110 Rep Power: 5	If you just need one of the spacers and a timing shim or two, I wouldn't worry about tolerance stacking - they are made for this specific purpose Now, if you need 3 or 4 spacers, that may be a different story. How long are your threads?