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muzzle brake reamers

I was wondering ya'lls thoughts on muzzle brake to bullet clearance. I.E.: if using a .264 cal bullet. what are the max/min clearances you would use for the brake internal diameter? i see PTG claims .015" clearance on their reamers. would .021" be too much? what is too much? thanks in advance


Matt
 
I was wondering ya'lls thoughts on muzzle brake to bullet clearance. I.E.: if using a .264 cal bullet. what are the max/min clearances you would use for the brake internal diameter? i see PTG claims .015" clearance on their reamers. would .021" be too much? what is too much? thanks in advance


Matt

First and foremost, check with the manufacturer of the brake itself for their specs for that caliber's exact brake. As an example, Harrels Precision advises .020, not give or take. The single most important factor in having the best and safest results is in the installation!

The bore size affects the turbulence surrounding the bullet upon exiting the barrel, hence accuracy. Without going into necessary detail, bore diameter, degree of square (rifle bore to brake bore) and brake bore size itself deserve utmost attention.

You didn't mention the brake itself that you plan on using. If you plan to bore brake yourself...I would highly, highly caution you. Be safe.
 
i am using hawkins precision brakes mainly. i have done a vais brake as well, both using the ptg reamers held in a floating reamer holder and the barrel dialed in to .0001" of bore. the reamers allow for me to use the live pilot bushing to align the bore and cut the centerline of the brake. i do not have a boring bar that will fit those tight diameters. i prefer the piloted reamers.


i was just wondering if using a .270 caliber reamer (which cuts .285" diameter hole) would be okay on a .264" caliber barrel?
 
I use mainly Harrels brake`s and dial them in off the original hole, drill them out to close, and finish with a chucking reamer .020 over bore size..
Never noticed that .001 + or - made a difference in accuracy....
 
.020 on most but have tested from .002-.050 over bullet diameter. IME, .015-.025 works equally well. As others have mentioned, it's most important that it be bored concentric and parallel to the barrel bore. For best accuracy, I want equal pressure around the bullet. For this reason, I prefer brakes that have ports opposing each other around the brake, rather than big ports on the sides and small holes on top, for example. I can't prove a significant difference but it seems only logical to me.
 
.020 on most but have tested from .002-.050 over bullet diameter. IME, .015-.025 works equally well. As others have mentioned, it's most important that it be bored concentric and parallel to the barrel bore. For best accuracy, I want equal pressure around the bullet. For this reason, I prefer brakes that have ports opposing each other around the brake, rather than big ports on the sides and small holes on top, for example. I can't prove a significant difference but it seems only logical to me.
I just put them in a lathe and open them 20-25 over with a screw machine drill
 
Bore them with a boring bar when fitting in a lathe. This will assure the hole is concentric to bore. A reamer will just follow what is there if it's concentric or not.

Indeed. Muzzle brake reamers have no place in precision rifle building. I assume some don't have a boring bar small enough. I have indexible boring bars down to .249" minimum diameter bore.

--Jerry
 
I have a very nice indexable carbide shank boring bar that fits into a .236" hole. Got another carbide shanked boring bar that I got off here for a super deal...not sure the bore diameter though. .250-.260 maybe...
 

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I have a very nice indexable carbide shank boring bar that fits into a .236" hole. Got another carbide shanked boring bar that I got off here for a super deal...not sure the bore diameter though. .250-.260 maybe...
I have sold a few thousand brakes and never used a boring bar on any of them
 
I bet the gunsmith that installed them did though
That could be but I have installed a bunch of them and always used a screw machine drill to open them up. 90 percent of the brakes I sell are opened up for a caliber before I ship them by me using a drill
 
That could be but I have installed a bunch of them and always used a screw machine drill to open them up. 90 percent of the brakes I sell are opened up for a caliber before I ship them by me using a drill
Have you run an indicator in fore and aft of the brake bore after the install? I'd be surprised if that needle stayed still. Regardless...clearance is clearance regardless the method. Make a difference either way?....doubt it. I prefer boring them out with a boring bar to make it the best possible. I got away from using brakes on my target barrels anyhow so I don't do many. Time is money in your case...
 
Have you run an indicator in fore and aft of the brake bore after the install? I'd be surprised if that needle stayed still. Regardless...clearance is clearance regardless the method. Make a difference either way?....doubt it. I prefer boring them out with a boring bar to make it the best possible. I got away from using brakes on my target barrels anyhow so I don't do many. Time is money in your case...
Its not about time or money--If I thought I needed to use a boring bar and it would make a difference I would use one.. I have brakes on all my rifles and they shoot very well some in the one's and I used screw machine drill on them to open the hole. There is nothing wrong with using a boring bar it's all about how you want to do it
 
rem40xb1,
it has nothing to do with the quality of your muzzle brakes. Assuming they are perfect, the tolerances on the muzzle brake threads and shoulder can result in the bullet not passing through the baffles perfectly centered. I would never install a pre-drilled muzzle brake on a precision rifle for myself (If someone brings me a muzzle brake predrilled and says to install it, I'll do my best).

but to install a muzzle brake correctly, you must put the barrel in the lathe set up perfectly around the axis, so why not jut bore the brake once you have it threaded and installed. If a brake is predrilled .020 over, I'll go ahead and open it up a few .001". Especially on a low energy round, more centerd is more important than more recoil reduction.

Using a boring bar to pre-drill will do nothing to help. The boring bar is used after install to match the centerline.

I just reinstalled a brake on the new barrel last week and had to open up .004" to get the hole centered. If I hadn't done this, the brake would have slightly deflected each shot.

You should do what your customers ask for, but if I were you I'd recommend that they have the gunsmith who installs them open them up to .020 over.

--Jerry
 
rem40xb1,
it has nothing to do with the quality of your muzzle brakes. Assuming they are perfect, the tolerances on the muzzle brake threads and shoulder can result in the bullet not passing through the baffles perfectly centered. I would never install a pre-drilled muzzle brake on a precision rifle for myself (If someone brings me a muzzle brake predrilled and says to install it, I'll do my best).

but to install a muzzle brake correctly, you must put the barrel in the lathe set up perfectly around the axis, so why not jut bore the brake once you have it threaded and installed. If a brake is predrilled .020 over, I'll go ahead and open it up a few .001". Especially on a low energy round, more centerd is more important than more recoil reduction.

Using a boring bar to pre-drill will do nothing to help. The boring bar is used after install to match the centerline.

I just reinstalled a brake on the new barrel last week and had to open up .004" to get the hole centered. If I hadn't done this, the brake would have slightly deflected each shot.

You should do what your customers ask for, but if I were you I'd recommend that they have the gunsmith who installs them open them up to .020 over.

--Jerry
Like I said I have sold brakes for several years and never had a problem..I have installed them on customers rifles and never had a problem.. I sell over a thousand every year and I don't have a problem with anyone.. I sell to several gunsmiths and open the brakes before I send them--again no problem---Maybe I am just real lucky
 

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