Indexing muzzle brake of of crown/muzzle

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18-08-2021, 10:33 PM
Stocky

Indexing muzzle brake of of crown/muzzle
So I have a rifle with a 7mm bore and a .560 muzzle diameter threaded to 1/2x28. I picked up a muzzle brake to fit and I notice the threads are not quite as tight (while doing it up seems fine once against the shoulder) as my other rifles that where specifically threaded to fit a specific muzzle device.

I'm curious about muzzle brakes that can index off the muzzle instead of a shoulder and whether this is an issue for accuracy.

Here are my concerns
- Not much meat left with a 1/2x28 thread on a 7mm bore.
- With the brake not being a snug fit I fell there's a lesser ability to resist the muzzle opening up.
- I'm not really wanting to chop the barrel but could suck up losing 15mm if it meant I could thread the barrel 9/16x24 with no shoulder and index of the muzzle.
I will offcourse (once we are out of lockdown) shoot the setup but we are locked down so thought may as well have a backup plan.
18-08-2021, 10:47 PM
Hunty1

Loctite?
18-08-2021, 11:10 PM
Stocky

Quote:

Originally Posted by Hunty1

Loctite?

The brake will stay on fine. The "issue" is more without the muzzlebrake being a. Tight fit there's nothing stopping the quite then muzzle flaring out. The breaks not loose but all my other threads don't have any play from about 3 threads whereas this has just a little jiggle until it shoulders up.
19-08-2021, 12:26 AM
TeRei

Reason why we have always taken our rifles to DPT to get done in person. Too important to get it messed up. Similarly protect your threads when not in use.
19-08-2021, 12:30 AM
Stocky

Quote:

Originally Posted by TeRei

Reason why we have always taken our rifles to DPT to get done in person. Too important to get it messed up. Similarly protect your threads when not in use.

Brought rifle threaded by previous and its quite the trip to DPT from down here. They have done a few of my previous rifles when I live up in the Bay.
19-08-2021, 06:40 AM
Hunty1

I'd shoot it first, might not be an issue. If it is maybe go see gunworks for a more appropriate thread.
19-08-2021, 08:56 AM
6x47

Yeh, the big question is why the hell do they still even use 1/2" threads on centrefires, certainly anything above .22 cal??
19-08-2021, 09:12 AM
Shamus_

Quote:

Originally Posted by Stocky

So I have a rifle with a 7mm bore and a .560 muzzle diameter threaded to 1/2x28.

Quote:

Originally Posted by 6x47

Yeh, the big question is why the hell do they still even use 1/2" threads on centrefires, certainly anything above .22 cal??

TBH while 1/2x28 is not ideal, in this situation there isn't much room for a larger diameter thread.
19-08-2021, 09:13 AM
6x47

Soda straw special..
19-08-2021, 10:01 AM
7x64

Quote:

Originally Posted by GDMP

Because in many cases there is not enough meat in the barrel for a larger diameter thread,and still enough behind it for a shoulder that a muzzle device can index against.

GDMP possibly knows a thing or two about this…. :thumbsup:
19-08-2021, 11:33 AM
Cordite

Two thoughts.

- Try a thin copper washer between shoulder and brake to help indexing, or jam in a bit of greased cotton string!

- If the problem is that the brake threads themselves are a bit clunky or loose, you can take up play by heating the brake enough to melt some lead solder into the (female) brake thread, should not affect hardening or tempering.
The solder is an old trick armourers used on Lee Enfield firing pin thread to remove play between firing pin and cocking piece and thus facilitate consistent pull off.
The alternative technique was punching a "W" in the (male) firing pin thread, but the equivalent of that would be to punch the "W" into the barrel thread, so not a great idea.
19-08-2021, 12:40 PM
Stocky

I think its needs to be clarified again that there is no real issue with the threading just hypothetical ones. Im not as worried about indexing as it is a radial brake so maybe the wording should have been shouldering against the muzzle vs a shoulder.

Quote:

Originally Posted by 6x47

Yeh, the big question is why the hell do they still even use 1/2" threads on centrefires, certainly anything above .22 cal??

Quote:

Originally Posted by Shamus_

TBH while 1/2x28 is not ideal, in this situation there isn't much room for a larger diameter thread.

The threads appropriately sized you would struggle to get enough shoulder for convential mounting or some people just ask for the thread they have already on their muzzle device.

Quote:

Originally Posted by 6x47

Soda straw special..

Nothing wrong with a soda straw :thumbsup:

Quote:

Originally Posted by Cordite

Two thoughts.

- Try a thin copper washer between shoulder and brake to help indexing, or jam in a bit of greased cotton string!

- If the problem is that the brake threads themselves are a bit clunky or loose, you can take up play by heating the brake enough to melt some lead solder into the (female) brake thread, should not affect hardening or tempering.
The solder is an old trick armourers used on Lee Enfield firing pin thread to remove play between firing pin and cocking piece and thus facilitate consistent pull off.
The alternative technique was punching a "W" in the (male) firing pin thread, but the equivalent of that would be to punch the "W" into the barrel thread, so not a great idea.

The brake fits fine just not perfect like the other threads that are snug even when only halfway threaded on. Theres not risk of it coming off the thread is more about whether there is any insight into indexing of the muzzle vs a shoulder to allow a larger thread to be used.

Quote:

Originally Posted by GDMP

Because in many cases there is not enough meat in the barrel for a larger diameter thread,and still enough behind it for a shoulder that a muzzle device can index against.

Have you ever indexed of the muzzle rather than a shoulder to allow a larger thread to be used. A 9/16x24 thread would effectively leave me all the barrel meat with no shoulder. so would require the brake (radial) to shoulder from the muzzle?