Muzzle break question?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by larryaguilar, May 5, 2003.

  1. larryaguilar

    larryaguilar Well-Known Member

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    Jan 10, 2003
    I have a sako 75 26" barrel 300 Weatherby
    I shoot 190 SMK @ 3060 FPS

    If I put a Muzzle Break on it will
    it affect the speed???

    Mag-na-port muzzle breaks - what do you guys
    think. Any other suggestions welcome

    going to the range on wed - will list all specs on the load

    Thanks
     
  2. sniper2

    sniper2 Well-Known Member

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    montana muzzle brakes will give a 100 fps increase. I loaded identical loads in my 338/300 and one belonging to a friend(his had the Montana brake) and fired the different rifles over a chronograph the one with the Monmtana brake shoot 100 fps+ faster and this was out of a shorter barrel, hell I wouldn't have believed it If
    we hadn't done the test!!!
     
  3. Brent

    Brent Well-Known Member

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    Sniper2,
    I was checking a factory load over the Oehler 35P last fall in my 300wm and a buddy had his there too. Mine was a 700, his a Ruger 77 mk11. Both had 24" bbls and his shot 125 fps faster on average with the same factory box of ammo. This has been my experience with Rugers though, they seem to get a little better speed than the others for some reason... all else being the same. His wasn't a Ruger was it?

    Theoretically, there is potential for some extra velocity, as some pressure is still behind the bullet even though the bore is larger in the brake and alot of pressure is vented off as it passes by the vents. The rifling is not slowing down the bullet any longer but, how much this ofsets the larger bore and progressive venting is anyones guess. A 100 fps gain in two or three inches of bbl is possible, but still a guess unless you remove it and then compare to yours. Did you remove it, and were they then both the same? Interesting.
     
  4. Darryl Cassel

    Darryl Cassel Well-Known Member

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    Brent

    That would be the best way to test this theory. Shoot it with the brake and then shoot it without. THE SAME RIFLE. I have done this and there was NO difference in velocity.

    As mentioned, the bullet is not touching any steel as it passes through the break. Most brakes need .016" to .022" clearance around the bullet to work well.
    Even though the brake may be 2 or 3" longer it is NOT the barrel with rifling in it.

    We know that every barrel is different and as the cutter bores the barrel at the factory it wears and there is a slight difference in land depth as this happens. If someone gets a barrel when the cutter is about to be changed, the rifling will not be cut quite as deep as a new cutter will allow.
    This is extreme but just a .0001" or .0002" could make a heck of a differance if it happened.

    Just a thought.

    My experiance is, there is no increase in velocity with a break on.

    DC [​IMG]
     
  5. Brent

    Brent Well-Known Member

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    I agree completely. One thing I noticed with both my Ruger .338wm's, was with 250gr Barnes X bullets, I never had any problem reaching the lands.

    I have had with all the Remingtons, including the 300wm.

    The lack of freebore to reduce pressure in the 700's may be why they yeild a little less velocity than all the various Rugers I've had experience with.

    I wonder what type chrono was used as well.

    The brake on-off test will tell the tale, gun to gun doesn't at all, but is still interesting to see the difference between the rifles. [​IMG]
     
  6. 4mesh063

    4mesh063 Well-Known Member

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    There may be a velocity gain but I'd bet the farm it's not 100fps or anywhere near. My gun w/wo brake makes no noticible difference in speed. I made a VERY tight brake for a 308 cal that was .315 ID and if it did help the velocity it make up for all that speed in accuracy. Shot terrible. I was told as Darryl says that .015 or so is the best number so I made a brake and tried it closer, .015 and opened up. I would say that .015 or more per side is fine.

    Another side note. The effectiveness of a muzzle brake is inversly proportional to the bullet weight to powder charge weight. In other words, a 220 swift is the king of recoil reduction and an efficient round, like a 7 BR or a 300 savage will benifit far less. A WSM lets say, will benifit, but not as much as your 300 weatherby.
     
  7. QuietHunter

    QuietHunter Well-Known Member

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    Others may know more about this, but having talked to Kevin Knight at muzzlebrake.com , he indicates that his muzzlebrake can actually increase velocity. It is an extension to the barrel, trued and crowned.
    I also think it is one of the better looking brakes as it is matched with the barrel. I really like the one he put on my gun. It is worth giving him a call.

    I think others on this site either provide or have used others brakes, so hopefully not stepping on any toes.

    In a world with lots of options, I have not heard of anyone using Magnaport in some time. I do not really like the looks of the large brake at the end of the barrel.
     
  8. Mysticplayer

    Mysticplayer Writers Guild

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    A muzzle brake will not affect the speed of the bullet.

    Magna porting is one of the least effective means of recoil control. Look at the Brownells or E. Arthur Brown website to see the many different shapes and designs available for muzzle brakes.

    There are really two categories: expansion and baffle brakes. The expansion brakes are like the KDF, BOSS, and Weatherby style. An extension with a bore much larger then the bullet. This brake will have holes around the periphery of varying size and pattern. Work quite well, from 45 to 60% recoil reduction depending on port volume and cartridge.

    The baffle brakes are like the fish gill brakes seen on 50cals, JP Ent, etc. Very effective, usually bigger in size and diameter. Effectiveness is a byproduct of number of gills and port/muzzle pressure. Usually better then expansion only muzzle brakes.

    In either case, the more gas that can be diverted 90deg. to the bore, the better. The bigger the port volume the better. Lots of small holes or a few big holes really doesn't matter as long as the volume is the same.

    Quiet brakes usually have lower recoil reduction then "noiser" brakes- allow more gas to be vented forward.

    The most effective brake is the baffle brake that vents backwards - see most 50Cals. Also, the noisiest, highest muzzle blast.

    Jerry
     
  9. Guest

    Guest Guest

    There is a third design concept to brakes that was not mentioned. Inertia/Vortex brakes, we use these to control recoil and torque, they are a quantum leap forward in both recoil reduction and accuracy. [​IMG]
     
  10. Guest

    Guest Guest

    I noticed some of you cut your brakes to pretty tight dimensions. Just as a note to keep in mind, any brake with .015" to .022" clearance should be checked on a regular basis. What happens is that the powder from these slower burning large cases peens the edges and rolls them up over time, physically shrinking the diameter of the opening. The bullet jacket will begin to rub and accuracy will suffer greatly. [​IMG]
     
  11. Celt

    Celt Active Member

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    It also depend on the hardness and material the brake is made from.
    The Answer brakes I install are made from either 416R SS or 4150. Both are heat treated to 28-30R. For a 30cal brake, the best recoil reduction and accuracy come from an .323" diameter hole through the brake. A maximum of .328".
    Never had one that closed up when the heat treat was right. Did see one that the heat treat was bad on and the brake visibly streched though.

    FWIW
    Celt
     
  12. Sabot

    Sabot New Member

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    May 6, 2003
    Celt -

    I use the Answer brake and it is an outstanding product, particularly when mated with the Answer recoil pad, which has a compression rate matched to the caliber of the rifle (mine is a 7 pound 416 REM). The pad is set to compress 5/8ths of an inch when the bullet enters the brake, so the bore thrust is managed by the pad and then the redirected gasses stop the momentum right there.

    The more overbore the round and the slower the powder, the better the brake works. Its just a matter of how much energy the gas has when it expands into the brake.

    If the brake is optimally effective, there will be no increase in velocity.
     
  13. daveosok

    daveosok Guest

    The breaks I use have an internal taper. The taper apposes the angle to which the gas contacts it at.
    Consequently, the muzzle breaks I have made are very effective. In my 7mm STW the opening is .320 or so. I found that anything tighter would effect my accuracy.
    Roy Bertalotto, who is a member on this board, has done some interesting work with muzzle breaks.
    S1 how did you overcome the colapsing of the bore at the end of the muzzle when the break tightened down?
    I understand now what you meant by anit-torque break, I thought you were suggesting that the muzzle break (before the bullet exited) counteracted the forces of the bullet in the bore creating torque.

    [ 05-06-2003: Message edited by: daveosok ]
     
  14. Guest

    Guest Guest

    Daveosok,

    Changing the angle of the threads, fine threads, and matching every thing to the O.D. and I.D of the barrel, and getting the torque right for the cartridge.