Muzzle Brake Question, Ruger Precision Rifle

[LRNut]

If the bore diameter of a muzzle break didn't matter, manufacturers would not make them in different sizes. It seems to me it is basic physics that the more oversize the diameter, the less gas will go through the ports.

 

[capona]

The size of the exit hole doesn't make a difference in the reduction of perceived recoil.

As such, It makes sense that manufacturers would standardize on the largest hole .30 to cover smaller calibers in that caliber group.

Now a suppressor would be a different story relative to sound suppression.

 

[FromAfar1969]

Nathan Wright at muzzlebrakesandmore.com is your guy. Check his videos out on Youtube. Top Quality, affordable , you won't be sorry.

 

[kgunz11]

Rule of thumb we use is exit hole is 10% larger than bullet caliber.

 

[TX Badger]

This is total amateur physicist speculation, but I can't see a hole in my thinking. The gas is going to follow the path of least resistance. If the bore through the brake is oversized enough, more and more gas will go forward and less will go out through the ports. Eventually this will mitigate the recoil reduction.

Extreme examples often help me visualize these things. What if the bore diameter through the brake was one inch. You can imagine that most of the gas would go straight forward and recoil reduction would be next to nothing. Somewhere between 20 thousandths oversized and 692 thousands there is and arc where the recoil reduction goes from Maximum to near-zero.

 

[Tex_Hunter]

It has nothing to do with the efficiency of the brake, and probably everything to do with two key things:

1) Cost: Ruger can just crank out a whole bunch of one sku regardless of their planned demand for the individual calibers of RPRs the think they will build/sell

2) Warranty/Quality: dont have to worry about one of the line techs reaching into the 6mm parts bin when they are building a 30cal RPR

A lot of the suppressor manufacturers do the same thing. My Dead Air muzzle brake on my 223 AR (even though it is threaded 1/2x28) is a 30cal brake, still noticeably reduces recoil even when I dont have the can on.

 

[Pat Byrne]

Just to muddy the waters, I installed a couple of Ross brakes.. I only have experience with a few brands but this one has less felt concussion to the shooter than the others I have tried. But this is on a .308, a larger round may be different. I've always heard .015 - .020'' over bullet diameter is where ya want to be..

 

[GLTaylor]

X2. I can't "feel" a difference using my 338 brake on my 6.5

 

[Chas1]

I've seen them as much as 40 thousand over.

 

[FEENIX]

X2. I can't "feel" a difference using my 338 brake on my 6.5

Depending on the chambering, the 6.5 has lesser recoil than a .338, i.e., .338 WM with 225g bullet vs. 6.5 CM with 125g bullet; this might explain why you cannot feel the difference.

 

[pony doctor]

.331 is well into 30 cal size. Most of my 30 cal run .321-.324.

i have the Thunderbeast supressors, ( 2 of them). The smaller for my Ar 556 and the other 9 inch for 300AX or anything 30 cal or smaller, ie. both are built for max 30 cal and work quite well on either rifle! Just my fwiw!

 

[Varmint Hunter]

I just put a Pain Killer (PK) brake on my 30Nosler. All I can say is that the reduction in recoil is NOTICEABLE. Kirby makes a very effective brake. The brake was specifically bored for a 30cal bullet.

 

[spladi]

I removed the muzzle brake from my 6mm Creed Ruger Precision Rifle. It appears that it's plenty big enough to allow use on a 30 cal rifle, which is what I'd like to do.

Are all the muzzle brakes on RPR's (30 cal and smaller) the same diameter? I'm measuring it at about 0.331" and a 308 bullet falls right through.

Thank you, Guy

Not a precision but both are Ruger LRT's with factory breaks, one a 6.5 Creed and the other a .300 Win Mg. , both break ID's measure .340" in diameter.

 

[Roy J Couvillion]

I removed the muzzle brake from my 6mm Creed Ruger Precision Rifle. It appears that it's plenty big enough to allow use on a 30 cal rifle, which is what I'd like to do.

Are all the muzzle brakes on RPR's (30 cal and smaller) the same diameter? I'm measuring it at about 0.331" and a 308 bullet falls right through.

Thank you, Guy

We tested the effects of bullet-brake radial clearance on ballistics. In our application, we found that smaller clearances would more likely induce yaw on otherwise stable bullets.
The assumption is that asymmetric alignment between the bullet path and the brake's circular hole left an asymmetric layer of muzzle gases about the bullet. That would lend to an asymmetric force about the circumference of the bullet, which would presumably induce yaw.
We also found that increasing the distance between the muzzle and the brake hole reduced the likelihood and/or amplitude of yaw. Apparently, removing muzzle gases from the bullet at a point where the muzzle gases are less dense reduces the amount, if not the distribution, of asymmetric forces.
That said, in our application, we determined Goldilox zones for 30-cal (0.348"), 6.5mm (0.302"), and 6mm (0.281").
Please note that these "zones" presume alignment with machining tolerances common to many quality barrel manufacturers. Also, know that the "muzzle brake" hole in our device is much farther from the muzzle than a dedicated brake. Given that your brake is much closer to the muzzle, it would follow that a 0.331" hole on a high-quality brake installed on a properly prepared muzzle would be just about right for a 30-cal round.
If you're suspicious about the barrel/brake/caliber combination, use an alignment rod (Brownell's has them) to check concentricity. Punch holes at ~50 yards and 100 yards to check for yaw.