Gunsmithing O index muzzle break barrel threading?

[rookie67]

I ordered one of Ross Shulers muzzle breaks with vents on the side and 3 holes on top, bottom is solid meaning it needs to thread on the barrel exact for the 3 holes to be aligned at o degrees on top. I'm dropping it and my rifle off at my smith tomorrow, he has never done one of these 0 index breaks before. Break threads are 5/8 x 24 and is tapered down to .823" for a flush fit 5/8" back from the muzzle.

Is there a trick to doing this or can someone give me information that I can pass on to him regarding the threading of the barrel? He's a competent gunsmith and has threaded many barrels before, just not one for a 0 index (if that's the right term?).

Any info is much appreciated,
Thanks,
Steve

 

[operator1]

Re: O index muzzle break barrel threading?

If your gunsmith can't index a muzzle brake, I think I would take my rifle elsewhere. IMHO

 

[jonaddis84]

Re: O index muzzle break barrel threading?

Not saying hes not, but I agree, indexing a muzzle brake should be included as part of being a competent smith.

5/8-24 moves 1/24" every 360 degrees of rotation. If it is 76 degrees from being indexed. [(1/24)/360]*76 minus .001 for crush and to make sure you dont go over and have to go another whole revolution.

 

[hero's machine]

Re: O index muzzle break barrel threading?

There is nothing to it. Just hack off the exact right amount and spin it on....of he does not hack off enough....hack off more, if he hacks off too much......hack off more.

One can save a lot of hacking with some careful measuring and a protractor. Use the tpi to get the proper hack and it can be nailed on the first try.

 

[rookie67]

Re: O index muzzle break barrel threading?

Thanks guys, i'll pass on jonaddis84's calculation to him and see what he says. He already told me that if he can't do it right the first time he won't do it at all.

Question on the formula jonaddis84, you mention if it's 76 degrees from being indexed...what is this degree measured from? Not sure what degree you are referring to. He'll probably know what this is, just asking for my own knowledge.

Thanks for the replies,
Steve

 

[Ratbert]

Re: O index muzzle break barrel threading?



You really need to get laid.

 

[rookie67]

Re: O index muzzle break barrel threading?

Thanks for the related info to this post, that reply was very creative and informative. You must have thought about that one for a while.

 

[x ring accuracy]

Re: O index muzzle break barrel threading?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ratbert</div><div class="ubbcode-body">

You really need to get laid.
</div></div>
LOL

 

[Killer Spade 13]

Re: O index muzzle break barrel threading?

Fine sand paper or emery cloth.

Keep equal pressure and force across the entire surface of the brake.

Set the threaded end of the brake on the sand paper and remove a little bit of material at a time until such time that when the brake is attached to the muzzle it is in correct alignment.

 

[danpd]

Re: O index muzzle break barrel threading?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">Fine sand paper or emery cloth.

Keep equal pressure and force across the entire surface of the brake.

Set the threaded end of the brake on the sand paper and remove a little bit of material at a time until such time that when the brake is attached to the muzzle it is in correct alignment. </div></div>

Are you being serious?

 

[Bill Larson]

Re: O index muzzle break barrel threading?

MUZZLE BRAKES...... big subject.... consider these facts:
1) o.d of barrel is seldom concentric with bore.2 lathe set- ups
2) adding one definately changes P.O.I.
3) adding one CAN affect accuracy
4) if you shoot prone... no holes out bottom
5) my OPINION ........Vais brakes work great
6)load 20 rnds. for b-4 and after test.
OMHO
bill larson

 

[rookie67]

Re: O index muzzle break barrel threading?

Thanks for the information Bill, I will perform the test you recommend. I'm considering getting a thread protector machined for times when I won't be using the break.

Steve

 

[jonaddis84]

Re: O index muzzle break barrel threading?

Call zero degrees straight up, however many degrees (estimated) from that point is what you multiply by how far it moves per degree.

 

[trilogymac]

Re: O index muzzle break barrel threading?

As said above, Find another smith. This is basic stuff.

 

[x ring accuracy]

Re: O index muzzle break barrel threading?

Simple to do. Not jumping on any bandwagon, but it is 101.

 

[STR]

Re: O index muzzle break barrel threading?

You can check out the you tube videos on channel suar08161991. You will find your answer on indexing there. Just can't remember which of the 52 videos shows it. The guy has all kinds of info there. Best of luck.

 

[my human host]

Re: O index muzzle break barrel threading?

I've done a few brakes but not the one in question. It's not a big deal. I've never felt the need to use a protractor. Just go slow and always take off a little less than what you think you need to. Nearly every brake needs to be timed to look right. For some it's a matter of function. Good luck.

 

[Killer Spade 13]

Re: O index muzzle break barrel threading?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cap'n Crunch</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">Fine sand paper or emery cloth.

Keep equal pressure and force across the entire surface of the brake.

Set the threaded end of the brake on the sand paper and remove a little bit of material at a time until such time that when the brake is attached to the muzzle it is in correct alignment. </div></div>

Are you being serious? </div></div>

Yes, very much so! Or if you're talented enough use a file or stone. Oh, I guess that I should have mentioned that I'm a toolmaker- machinist-mold maker. It's really not difficult at all.

However, if a lot of metal needs to be removed, then figure out how many degrees it needs to index for correct alignment. You should know what your thread pitch is. For most .30 caliber brakes it seems to be 24 TPI. This translates into approximately .042" per revolution. Carrying that forward, if you had to index your brake by, let's say 200 degrees (the top of the brake is lining up at about 5 o'clock) then (.042" / 360 deg)X 200 deg = .023". You'd need to remove 23 thousandths of an inch from the threaded end of the brake.

Or you could just put some shims between the barrel and brake.

 

[buffybuster]

Re: O index muzzle break barrel threading?

'0' degrees is TDC (Top Dead Center).

Your smith needs to mark that spot with the barrel still on the action. Then any angle measurements and alignment needs to be referenced from TDC. If everything was measured correctly, everything should line back up once it's put back together.

24tpi = 0.0417" per revolution. If the brake is half a turn off, then take about 0.020" off which allows of a crush fit. Adjust accordingly to how much of a rotation you are off. Once every thing is timed, you can blend it.

Really basic stuff.

 

[rookie67]

Re: O index muzzle break barrel threading?

Thanks everybody for the relevant comments, I showed this posting to my smith, will post when I get it back.

Thanks again,
steve