Muzzle brake for 300 Weatherby Mark V

A/1-61

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Massachusetts
I am having trouble deciding what the correct move is for a muzzle brake for my 300 Weatherby Magnum, Mark V, bought circa 1980. To start with, the outside diameter of the barrel at the tip is .610. I believe this means that I need to find something with a 1/2 by 28 thread. Otherwise I would have to shorten the barrel to a point where a 5/8x28 would work which was the recommendation from a local gunsmith.
.
Secondly, Weatherby only cells one type of break with portholes around the entire diameter, which makes it difficult for prone shooting if you don't like a mouthful of dirt. I have also heard of CSR brakes but don't know much about them. I have questions on whether a 1/2x28 is safe to use or not. Does anybody have experience with adding a break to a Weatherby?.
 
a friend replaced one with an aftermarket and found the factory one to be much better at recoil reduction. It was a 30-378 and said it felt like someone was punching him in the jaw till he put the factory one back on.
 
a friend replaced one with an aftermarket and found the factory one to be much better at recoil reduction. It was a 30-378 and said it felt like someone was punching him in the jaw till he put the factory one back on.
Same here with the recoil. 50 lb of kick, I am told. It was manageable 40 years ago when I had a bicep, but now at 76 it is recoil pad against bone.
 
a friend replaced one with an aftermarket and found the factory one to be much better at recoil reduction. It was a 30-378 and said it felt like someone was punching him in the jaw till he put the factory one back on.
I have two factory Weatherby with factory radial brakes. I have two Weatherby with gunsmith installed brakes. All are radial. I don't have a problem but then again I don't do much prone. You can always throw a piece of cloth/canvas on the ground around where the muzzle would be.
Your circa 1980 would be Japanese. I have one of those rifles with factory brake. Personally I like the factory!
 
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the weatherby design and similar is supposed to be the most accurate from what I was told by a knowledgeable br competitor and gunsmith. He built and installed a very similar one for a thin barreled 6.5-300 vanguard for my brother.
 
Weatherby's stock thread for a #2 barrel is the 1/2-28. They work well.
I have even used this thread for my suppressor with an adapter on my 300 Weatherby without issues.

There are a few skinnier Weatherby barrels (Ultralights, Backcountry) but the 1/2-28 should work for you.
If you have a Weatherby service center near you they may be able to install the previous version of the Accubrake for you. Those you could get in blued steel, not just Cerakoted like the new ones.
 
I am having trouble deciding what the correct move is for a muzzle brake for my 300 Weatherby Magnum, Mark V, bought circa 1980. To start with, the outside diameter of the barrel at the tip is .610. I believe this means that I need to find something with a 1/2 by 28 thread. Otherwise I would have to shorten the barrel to a point where a 5/8x28 would work which was the recommendation from a local gunsmith.
.
Secondly, Weatherby only cells one type of break with portholes around the entire diameter, which makes it difficult for prone shooting if you don't like a mouthful of dirt. I have also heard of CSR brakes but don't know much about them. I have questions on whether a 1/2x28 is safe to use or not. Does anybody have experience with adding a break to a Weatherby?.
I have a 1/2x28 break on a .340 Wby and it has been on there 28 yrs, no issues whatsoever. I also have one on a Sako .300Wby and no issues with it either. My cousin has the same on his .340 and although it is only 8 or so yrs old, he has shot it probably in the neighborhood of 300 times with no issues, well except it broke a scope mount once. 😅
 
I am having trouble deciding what the correct move is for a muzzle brake for my 300 Weatherby Magnum, Mark V, bought circa 1980. To start with, the outside diameter of the barrel at the tip is .610. I believe this means that I need to find something with a 1/2 by 28 thread. Otherwise I would have to shorten the barrel to a point where a 5/8x28 would work which was the recommendation from a local gunsmith.
.
Secondly, Weatherby only cells one type of break with portholes around the entire diameter, which makes it difficult for prone shooting if you don't like a mouthful of dirt. I have also heard of CSR brakes but don't know much about them. I have questions on whether a 1/2x28 is safe to use or not. Does anybody have experience with adding a break to a Weatherby?.
No, you do not have to shorten your barrel. Find yourself another gunsmith. A competent/reputable can build you an adapter with a shoulder and convert your rifle's 1/2-28" muzzle thread to 5/8-24" so you can use a 5/8-24" muzzle device (muzzle brake or suppressor).



Or you can purchase a 1/2-28" to 5/8-24" adapter.


Since yours is already threaded for 1/2-28", you can go with a self-timing muzzle brake, and there are plenty of them to choose from. I like Nathan's (https://muzzlebrakesandmore.com/beast-2-piece-brakes) offerings. Below is a Ross muzzle brake. It is probably the most budget-friendly but not as effective as Nathan's. It still provides a better felt recoil and muzzle rise reduction than the radial brake, not to mention blowing debris when shooting prone.

1711708264226.png

(https://www.rossbrakes.com/shop)
Here is Nathan's test on .300 WBY. The first muzzle tested was a radial brake similar to your factory brake.

 
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My Smith put a 1/2x28 brake on my 300 weatherby thin barrel. I am almost positive it was a Micro Bastard brake. It really tames out the kick on the 300 weatherby for how small it is.

 
I shot my Mark V Weathermark LT in 7mm Weatherby Magnum without the break first when i was doing the barrel break in.
Screwed the break on, just to see how that was.
Now I just leave it on.
This is the factory radial break.

Thinking of having the barrel threaded on my Ultra Lightweight in 257 WBY Mag.

I have a 3 port break on my Savage 111 in 7mm Rem Mag.
 
Precision Armament makes a thread adapter 1/2-28 to 5/8-24 in Stainless Steel or matte-black PVD. They're about $30 bucks and Brownells has e'm in stock.They also sell 9/16-24 to 5/8-24, for $29- $36 bucks.
 
Have your smith cut M15x1 threads on your barrel, this is .590" OD and the minor diameter is .550" this will give you the most barrel wall thickness. Then have him make a simple adapter bushing with 5/8-24 on the outside and M15x1 inside. Problem solved without harming your barrel!
 

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