Muzzle Brake Installation

[brant89]

So I've been pondering how the process of installing and indexing a brake is done in detail and I'd like to hear more about it. As an engineer, I know how I would do it, but a lot of times machinists have tricks that can make things easier. Here are my questions.

1.) When cutting new threads on a barrel, do you use a caliber specific rod in the bore to indicate the chuck to ensure the threads are concentric to the bore?

2.) Do you have to cut a new crown when you thread a barrel?

3.) When installing a brake that requires indexing (like an APS PK) do you guys prefer to receive a barreled action or the two parts separate and then you set headspace and index the brake?

4.) When indexing a brake without using shims I'm assuming you just chuck the brake in a lathe and remove the correct amount of material to get the proper indexing. Is this correct?

5.) Do you ream the brake for the correct bore size before or after it is mounted on the barrel?

Sorry if these are "noob" questions. Like I said, I know how I would do it but I'd like to hear from some guys who actually do this.

 

[J E Custom]

So I've been pondering how the process of installing and indexing a brake is done in detail and I'd like to hear more about it. As an engineer, I know how I would do it, but a lot of times machinists have tricks that can make things easier. Here are my questions.

1.) When cutting new threads on a barrel, do you use a caliber specific rod in the bore to indicate the chuck to ensure the threads are concentric to the bore?

2.) Do you have to cut a new crown when you thread a barrel?

3.) When installing a brake that requires indexing (like an APS PK) do you guys prefer to receive a barreled action or the two parts separate and then you set headspace and index the brake?

4.) When indexing a brake without using shims I'm assuming you just chuck the brake in a lathe and remove the correct amount of material to get the proper indexing. Is this correct?

5.) Do you ream the brake for the correct bore size before or after it is mounted on the barrel?

Sorry if these are "noob" questions. Like I said, I know how I would do it but I'd like to hear from some guys who actually do this.

Briefly, question

#1. YES on both ends of the barrel.
#2. Only if it needs one.
#3. I like A head spaced barreled action so that the indexing is based on the action with it made up.
#4. I also prefer not to use shims and time the brake buy removing the right amount of shoulder from the barrel tenon for the brake to time the brake with it torqued up.
#5. I like to ream the brake after it is installed and timed so that the bore of the brake is perfectly
centered on the barrel bore. (Normally .020 to .025 larger than the rifle bore is the optimum bore diameter for the brake).

This is just the way I like to install a muzzle brake. Others may do it differently.

J E CUSTOM

 

[orwapitihunter]

#1 I run my indicator right on the bore in two places. One as far in as I can reach (about .75"), the second out near the crown.

#2 through #5 the same as J E Customs.

 

[brant89]

Thanks JE. I was secretly hoping you would chime in here.

So if you both prefer to have a barreled action that has already been headspaced, I'm assuming then that you chuck up the entire barreled action. Does this limit you on what barrel lengths you are able to do? Also, is there a particular reason for removing material from the barrel to index the brake vs removing it from the brake itself (other than the fact that you already have the barrel in the chuck)?

 

[J E Custom]

Thanks JE. I was secretly hoping you would chime in here.

So if you both prefer to have a barreled action that has already been headspaced, I'm assuming then that you chuck up the entire barreled action. Does this limit you on what barrel lengths you are able to do? Also, is there a particular reason for removing material from the barrel to index the brake vs removing it from the brake itself (other than the fact that you already have the barrel in the chuck)?

You are welcome.

Yes, I like to set the entire barrel in the Lathe spindle for the best alignment. Spindle length determines what barrel length you can use in this way. If the barrel is to short to set it in the spindle , then you have to make a choice either to remove the barrel and re head space it or set the barreled action between centers.

The main reason I like to remove material from the barrel shoulder is because I already have the barrel set true and It is just a matter of figuring just how much material to remove shy of where you will end up after torqueing. I can also level the action and use this as a benchmark for leveling the brake.

Doing all of this work with the barrel in the Lathe is the most accurate way to install any muzzle brake in my opinion because everything is based on the barrel bore.

Different actions and barrel lengths require different set ups and must be thought about before
installation to get the best results.

I am sure others will do things differently, But this is my way and opinion based on finished results.

J E CUSTOM

 

[Edd]

#5. I like to ream the brake after it is installed and timed so that the bore of the brake is perfectly
centered on the barrel bore. (Normally .020 to .025 larger than the rifle bore is the optimum bore diameter for the brake).

J E CUSTOM

What method do you use if the dividers/partitions between the ports are different diameters?

 

[J E Custom]

What method do you use if the dividers/partitions between the ports are different diameters?

The main thing is to make sure that the bore of the brake is at least .020 larger than the rifle bore.

Less gains nothing, and more reduces the effectiveness of the brake. If the partitions are larger,
the exit hole of the brake should still be .020 to .025 larger than the bore and perfectly centered on the bore to contain most of the gasses to get the efficiency and reduce the backward thrust.

Different brakes have different methods of recoil reduction but the bullet must have enough clearance to prevent bullet strikes.

J E CUSTOM

 

[Hired Gun]

If a barreled action is too short to put through the lathe spindle I simply make a temporary timing mark on the barrel joint and another at 12 o'clock on the muzzle end. Then remove the barrel from the action. No need to reheadspace anything. It will be exactly as it was when returned to the mark. To make the barrel fit in the lathe I have a set of tubular extensions I made that are threaded internally to fit the different thread sizes on whatever barrel I'm working on. These are long enough to reach the outboard spider. Then I dial in the same way as doing my regular chambers or crowns by only dialing in the path of the bore on the end I am working on. For a crown it's just inside the crown and then 2" farther in. Then thread, time and bore everything based on that setup. We prefer to bore to .020" over the bullet size. No drills or brake reamers are ever used. I always throw in a fresh new 11 degree crown at this point setting the end of the barrel exactly flush with the first port in the brake. It's nice looking and always helps accuracy.

Here is a CSR stainless brake fitted to a Remington SPS barrel with the brake Cerakoted to closely match the factory finish. This one shows the new crown and flush to the first port fit. The end of the barrel will be blued to complete the look. When working with stainless barrels the joints will fully disappear. The end of the brake is sculpted how ever the customer wants it. This is our default when they have no preference. It's also 11 degree just like the end of our barrels that have no brake.