Gunsmithing Aluminum brake?

[veezer]

I had a 300 WSM rifle built a few years ago and the gunsmith made a three port brake for it of his own design (looks a lot like the badger thruster). I had never taken it off but decided today to try my can on it. I took it off and noticed it was made of aluminum! I have shot this rifle a lot and haven't had any issues but is it really safe to have an aluminum brake?


Dcerefinishing.com

 

[Kells81]

You sure it is Aluminum and not Titanium?

 

[Iamero]

Even if it was aluminum what would make it unsafe? The concussion from the bullet isn't going to damage it any. Just don't bang it against something harder haha.

 

[...]

if it were aluminum.....i would really only be worried about the hot muzzle gasses eroding the baffles of the brake ( similar to the flame cutting you see on scandium revolvers)

i really dont think structurally youll have to many issue with it honestly

 

[Wannashootit]

Aluminum threads will stretch with repeated removal/re-installation more than steel will which can cause issues with thread fit and timing in my limited experience with them.

 

[300sniper]

There's a lot of uncorking pressure of hot gasses at the muzzle. A muzzle brake works when this high pressure gas slams against the rear faces of the ports. Minimal strength and erosion resistance are two reasons I'd never use aluminum for a centerfire rifle muzzle brake, or any muzzle device.

 

[veezer]

It is definitely not Titanium. I think the guy was just cutting corners/cost when he made my gun and didn't tell me he was doing it either. I had never heard of anyone making an aluminum brake before and just thought it was very odd to trust something soft like aluminum to tame all that explosive gas. And, he put a bastard thread size on it too so I have to send it off to get the threads fixed to put my can or another brake on it.

 

[lash]

While I am not advocating for the use of aluminum for a muzzle brake, I do get a kick out of comments like "soft aluminum" and "minimal strength". Maybe you shouldn't know that almost all AR15, AR10 and M15 uppers and lowers are made from "soft aluminum" with "minimal strength".

Oh yeah, and with regards to him cutting corners/cost, I just did a reality check. Cold roll 1018 steel 1"x1.5" flat bar is $15.79/ft. Cold finish 7075 aluminum 1"x1.5" flat bar is $30.89/ft.

 

[MTFalconer]

Aluminum does just fine for a muzzle brake. When we were building out long action 50's (50 peacekeeper, 500 a square and 500 whispers) we played with all sorts of muzzle brake designs in the shop. All aluminum and never had an issue at all. 50 peacekeeper is a hell of a round and has pressures and muzzle velocities pushing a 50 BMG. If it was going to fail, it would have done it there for sure. Also remember "aluminum" is a really vague term. There are MANY alloy compositions out there. Without knowing what it is, schedule wise it's like calling a knife blade "steel".....

 

[Wannashootit]

120 mm. tank shells and 30 mm. cannon shells are aluminum cased. The lower melting point shouldn't be an issue for rec shooters.
Methinks the only reason what would be lighter, cheaper aluminum ammo in 7.62 NATO and 5.55 isn't used in the military is the incompatibility with automatic weapons.

 

[mcfred]

Erosion over time is the only concern I'd have. On a hunting rifle I wouldn't worry about it at all. Gas erosion is not as bad as high velocity particles of unburnt powder though. The particles may peen over the edge of the brake's inside diameter and if neglected could affect the bullet's flight through it eventually. I have a buddy with an aluminum brake on a .22 hornet with maybe a thousand rounds through it. The brake ports around the bore hole are pretty beat up, however it still shoots .25moa.

 

[300sniper]

While I am not advocating for the use of aluminum for a muzzle brake, I do get a kick out of comments like "soft aluminum" and "minimal strength". Maybe you shouldn't know that almost all AR15, AR10 and M15 uppers and lowers are made from "soft aluminum" with "minimal strength".

Oh yeah, and with regards to him cutting corners/cost, I just did a reality check. Cold roll 1018 steel 1"x1.5" flat bar is $15.79/ft. Cold finish 7075 aluminum 1"x1.5" flat bar is $30.89/ft.

I'm thinking the loading and operating conditions of a muzzle brake are quite a bit different than an AR15 receiver.

 

[...]

Oh yeah, and with regards to him cutting corners/cost, I just did a reality check. Cold roll 1018 steel 1"x1.5" flat bar is $15.79/ft. Cold finish 7075 aluminum 1"x1.5" flat bar is $30.89/ft.

i will just point out....that for machined parts....its not the material thats expensive.....but the machining time and setup.

i can generally machine aluminum 2-3x faster than i can machine steel....considering shop time is around $50-100/hr.....it adds up fast.

 

[lash]

I'm thinking the loading and operating conditions of a muzzle brake are quite a bit different than an AR15 receiver.

Oh, I agree. A muzzle break has to deal with the pressures and heat of the gasses coming out of a barrel and an AR15, M15, or AR10 receiver (less than 1/8" thick in spots) only has to hold together the steel parts that contain the controlled explosion, right next to your face, during mag dumps, over-gassed situations, and other high rate of fire situations. So no pressure or heat there...

 

[lash]

i will just point out....that for machined parts....its not the material thats expensive.....but the machining time and setup.

i can generally machine aluminum 2-3x faster than i can machine steel....considering shop time is around $50-100/hr.....it adds up fast.

You are correct. But in a typical small smith shop, making one-offs for each client, the set up time for a single piece far outweighs the machining time as far as cost goes. In a CNC volume situation, the speeds and feeds of machining time becomes a much bigger factor.

As a point of reference, where I work, we sold more than 800,000 pounds of aluminum chips to the metals recycling dealer just last year. And we are a small shop in our company.

 

[300sniper]

Oh, I agree. A muzzle break has to deal with the pressures and heat of the gasses coming out of a barrel and an AR15, M15, or AR10 receiver (less than 1/8" thick in spots) only has to hold together the steel parts that contain the controlled explosion, right next to your face, during mag dumps, over-gassed situations, and other high rate of fire situations. So no pressure or heat there...

Actually, correct. Very minimal pressure and heat is transfered to the aluminum (or polymer) AR15 receivers.