I was wondering if I have a gunsmith install a muzzle break on my rifle will it hurt or change the accuracy of the rifle.

The rifle is a .378 Weatherby Mag. Mark V Deluxe.
The reason I ask, is that the barrel is real thin at the muzzle. I'm thinking of getting one that is removable. Thanks

Scratch

IF it's done correctly, the addition of a muzzle brake should not affect your rifle's accuracy.
It will probably cause the POI to move (change in barrel harmonics), and it may improve your ability to shoot tighter groups due to less perceived recoil.

You should shoot with earplugs AND muffs, though.

George

Unlike porting, which cuts through the rifling, a muzzle brake with a full expansion chamber does not have any contact with the rifling at all. A muzzle brake may affect velocity but it should not affect accuracy. As mentioned above, POI will probably change for a particular load when switching from no brake to brake. Unless it is a custom rifle, your 378 WB should come with a removeable brake already from the factory. Good luck.

I shoot a 338-378 Wby with a brake. I did my initial load workup with the brake on. Taking off the brake did change the POI about 1 1/2 inches high and to the left. The group also opened up a bit. I blame barrel harmonics for both changes. There was no change in velocity shooting the same load over a chrony both with and without the brake. I minor adjustment to the scope to re-zero and a reducing the powder charge a grain or two, and the groups imnproved. When I do my job behind the rifle, it will shoot MOA either way.

Sctatch I had a muzzle break installed on a 300WBY and a 257 WBY [before I know better, I do not like a break, too loud]. They were done by Phil Koene of KDF in Seguine TX. He does excellent work. The rifles shot just as good if not better after the breaks were installed. It made the 300 WBY kick like a 243. It kicked MUCH less than a Rem Mod 7 in 308. They do work, but they are loud.

I have a Savage 112 with the adjustable muzzle brake(brake on, brake off). When I was developing my loads I was using a chronograph I checked shot strings with brake on and brake off. I found negligible differences in velocity (10-20 fps) with the brake open compared to closed. I also had no difference in POI. As a matter of fact, I got tighter groups with the brake open. Could be a recoil thing on that since it is a .300 RUM.

bowhuntr

I guess I'm forturnate, none of mine change POI with or without the brake. None ever have. Today i only use a brake of the worst of kickers like a 458 Lott or up. The brake is what taught me to shoot the really big bores. I still love them for benchwork.

Thank you everyone that replyed, I'm more than likely going to have to do something.

Every time I shot, the top shell down in the magazine gets the bullet pushed father down into the brass. Not to mention it flattens out the tip.

Mingo,

My .378WM never came with a muzzle break from the factory, maybe they do now. I bought this gun 15 years ago.

Thanks

Scratch

Russell E
Taylor

Crimping the brass will help, might even eliminate the problem.
My only question is (I'm shooting 300 grain Nosler Partitions and they have a cannelure) if I seat the bullet any deeper so I can crimp into the cannelure I'll be farther from my riflings.
Will this make any differnce since the Weatherby is freebored? Could I crimp the bullet good enough with a RCBS die?

Thanks

Scratch

Malm: I'll have to agree that a muzzle brake is likely to shift the point of impact, not because of it's effect on the recoil movement of the rifle, but rather because of its effect on the vibration characteristics of the muzzle.

The recoil movement of the gun at the time the bullet exits the muzzle is identical (or virtually so) in a braked and unbraked gun. It is only after the bullet exits the muzzle and the pressured gasses behind it have an opportunity to do "work" on the muzzle brake that the motion of the rifle is affected. The air in the 20 or so inches of bore in front of the chambered bullet that is pushed out in front of the fired bullet is not a significant factor affecting the brake.

As to the accuracy potential of a braked vs. unbraked rifle, in theory there should be little difference. In practice, I can't imagine being able to hit any thing with the second shot from a f*****g muzzle brake after the first shot blasted the s**t out of every living thing in a radius of 15 steps, including all of the orafices in my head. The most effective reduction in perceived recoil afforded by a muzzle brake is that you hardly notice your shoulder hurting when your head is pounding.

Stonecreek,

I share your enthusiasm of being in the immediate vicinity of weapons sporting muzzle brakes. They can be about as obnoxious as a drunk exwife at the front door.

It has been my experience though, that a properly constructed and installed muzzle brake, correctly aligned with the bore so as not to create a situation where contact with the bullet could occur, will not adversely affect accuracy. In fact, the only time I have seen a muzzle brake outright ruin accuracy is when they have come loose or blown off.

The use of a muzzle brake provides some benefits. Depending on the caliber and the muzzle brake, it is quite possible for the shooter to view the results of the bullets impact on the target and in a situation where a quick follow up shot is needed, the shooter can remain on or quickly reacquire the target for the necessary follow up shot.

A muzzle brake can instill confidence in the shooter. They allow the shooter to focus more on the target and less on the impending thump which no doubt helps accuracy.

Indeed they have their good points and they have their place, but sometimes in the presence of others as in "at the range", these positives are overshadowed by their distractions.

The down side to muzzle brakes include muzzle blast! Muzzle brakes by design provide an environment where debris and moisture can enter the bore from many directions. When shooting prone, some muzzle brake designs kick up enough dirt so as to blind or give away a shooters position.

Some people swear by them, and some people swear at them. If a person is going to have one installed, they should excercise common decency when using these in the presence of others and accept the responsibility for their safe use...

Malm

[ 01-20-2003, 21:54: Message edited by: G.Malmborg ]

I believe perhaps the fact that I use stress releived Lothar Walther barrels may have some sugnificance in the fact that my guns shoot to the same POI for all practicle purposes...However I have had a Lilja and several Douglas barrels that didn't change more than an inch at the most.
I am sure proper bedding, and brake installation is also a factor.

Send that 378 back to Weatherby and they'll install an Accubrake (KDF copy) for around $100.It won't void Weatherby's accuracy garuntee either.

Your 378 is an older one with #2 contour.Nice and light.I have one with a #3,and while it's nice,I'd much preffer a #2 for carrying.

Brian.

Brain M

I appreciate the information.
I just measured my barrel and it is a #3 contour. Are you sure about that price and why so cheap?
I take it that you have a .378 with a muzzle break, what caliber would you compare the recoil to?

Once again thanks
Scratch

Huh?How could it be a #3 Weatherby contour if you bought it 15 years ago?As far as I know,they didn't start making 378s on the #3,until after 1989,when the 416 came out with that contour.

Yup,I have a 378 with the Accubrake.Can't tell you anything though as I haven't gotten around to shooting it yet.Friends who own them claim they kick about like the average 300 Magnum with the brake installed.

Don't know why the Accubrake is cheap.They were $100 a few years ago.Wouldn't be suprised if they wanted more for them now.

Brian.

Brain M

I hate to think of it this way but I bought the gun right around the same year the space shuttle blew up.

I might be wrong but that was around 15 years or more.

I also bought a Weatherby Guide book (22nd Edition) copyright 1985. It gives the muzzle measurement of .640 for a .378 WM and that is what my barrel measured.

I e-mail Weatherby last night and asked if they could give me a price to install the break.

Brain, thanks for the information and good shooting.

Scratch

Scratch,
Does the booklet say that a #3 is .640 or does it just say the 378 in general comes with a #2?

As far as I know,the 378 in a #3,didn't come along till after 1989,since I don't think the #3 was even available until they brought out the 416.

A 378 with a #2 barrel ought to be REALLY light-like 8 pounds or less unscoped.

Brian.

Brain M

I just looked and double checked the book again to make sure I wasen't giving you the wrong information.

The book was writen in 1985.

"Quote"

No. 3 contour standard on .378 W.M.

"Unquote"

Then it gives you the measurement of the barrel in differnt location and the weight.

I found this book to be very helpful when it come to reloading. Weatherby tells you the overall length of each caliber. When I was trying to find a good group for my .257 W.M. it wouldn't shoot good until I seated the bullet to their spefications.

One more thing the No. 2 contour barrel was used on .340 .257 7mm and 300 W.M. And for additional money it was used on .22/250 .224 and .240 calibers.

Scratch

I stand corrected.I guess we both have #3s.

I do know though,that in the 70s,378s were made with #2 barrels.I have seen a few and those barrels were REALLY light.

Yup,used to be on 224-300 you could get #2 for extra money.I have a 22-250 with a #2 made in Germany.

Now,they don't offer any of the magnums with a #1,just the #2 and #3.

Brian.