5 R canted land barrels.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by ol mike, May 22, 2006.

  1. ol mike

    ol mike Well-Known Member

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    What do you guys think of these type barrels?

    I read of people getting more velocity and great accuracy out of the canted land barrels.
    And does anybody have expierence w/ mike rock barrels?
    Thanks Mike
     
  2. James Jones

    James Jones Well-Known Member

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    I have used a couple Rock Creek barrels and have nothing but great things to say about them ,they clean easly shoot fast and seem to last a good while. I also have an Obermeyer barrel and it is the same way , seemingly no fouling great velocity and very accurate.
    The Broughton barrels are supposed to follow the same suit but they are button rifled instead of cut rifled. Is their a differance between cut and buttoned? I can't tell , I have never chambered a gun in the same caliber and treated it the same with both to give an honest compairison. Cut rifled barrels are said to last longer.
     

  3. Bart B

    Bart B Well-Known Member

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    Barret (Boots) Obermeyer came up with his 5R rifling design soon after Sierra Bullets introduced their 7mm 168-gr. HPMK bullet my very good friend Tom Treinen used with a borrowed rifle and ammo in 1970 to break the 1000-yard scope sight match record at the highpower Nationals; 42 shots inside 20 inches, prone, windy conditions. Problem with those bullets was their jackets were a bit thin in order for Sierra to get uniform wall thickness for a very long jacket in that caliber. Those thin jackets were engraved a bit too much by conventional rifling and they would occasionally split at a engraved land mark and fly apart. Boots Obermeyer designed the 5R rifling so that less stress was made at the edges of the engraved groove in the bullets. That worked well enough indeed. But Sierra had problems making that bullet as accurate as their 30 caliber ones as jackets just couldn't be made to wall thickness uniformity quite as good as the 30 caliber ones. Those bullets Tom Treinen used were taken out of the final pointing machine as they were tested and found to be very accurate in firing tests.

    Meanwhile, Boots Obermeyer made some 30 caliber match barrels with 5R rifing. These shot as good and often better than his conventional rifling. His 5R became quite popular afterwords.

    Mike Rock was an apprentice under Boots Obermeyer and there's rumors/facts going around that Mike left Boots' shop under less than aimiable (hostile?) conditions. And Mike Rock took a lot of skills and knowledge with him. Including the 5R rifling design.

    I've used both conventional and 5R barrels from Obermeyer; both with the same bore and groove diameters. With the same load for .30-.338 Win. Mag. cartridges, muzzle velocity was within 10 fps of each other. Accuracy was too close between them to say one was better than the other; 15-shot groups at 1000 yards in the 5 to 6 inch range.
     
  4. lerch

    lerch <strong>SPONSOR</strong>

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    there is a good article on 6mmBR about bbl making methods.

    pretty interesting to read, covered cut and button pulled bbl's

    steve
     
  5. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    Is their a differance between cut and buttoned?

    [/ QUOTE ]Provided each is made with the same tolerances in dimensions and smoothness, I don't think so. In manufacture, button rifled barrels are easier to control groove diameter with; cut rifled barrels are easier to control bore diameter with. Properly made by skilled people using proper tools will show no significant difference in accuracy. Nor in barrel life if both are made with the same steel type.
     
  6. bailey1474

    bailey1474 <strong>SPONSOR</strong>

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    I've got a Broughton chambered in 6-250 that refuses to foul. I would say it's just a tad easier to clean than the 4 groove Lilja on my 300 RUM but way easier to clean than the 3 groove Lilja on my 270 AM. All are superbly accurate though.

    I cna't say that I've noticed the increase in velocity. I'm getting about 2970 fps which is right where I thought I should be.
     
  7. goodgrouper

    goodgrouper Well-Known Member

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    [ QUOTE ]
    Barret (Boots) Obermeyer came up with his 5R rifling design soon after Sierra Bullets introduced their 7mm 168-gr. HPMK bullet

    [/ QUOTE ]


    No offense to Boots but saying he came up with the idea of canted rifling is wrong. To say he was the first American to successfully adapt the idea to solve a thin skinned bullet problem would be more correct. He actually "borrowed" the idea from the Russians (which is what the R stands for in 5R) who were making barrels in this manner as early as WWII and possibly even earlier. Records of production were unfortunately destoyed in the Nazi battles for Russian ground.

    I do agree with you that they are good barrels and so are conventional rifled custom barrels if done properly.
     
  8. Chris F

    Chris F Active Member

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    I've had the good fortune to talk to Boots a bit about the origins of the 5R rifling pattern. Here are some of my recollections;
    A number of years back when the Russians introduced their 5.56x39 round, it caused a bit of concern and stir here. The US Gubmint got their hands on some rounds, but needed barrels to test the performance in firing. Boots was asked to run barrels in the Russian pattern for that purpose. Hence his introduction to and of the 5-R pattern.
     
  9. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    No offense to Boots but saying he came up with the idea of canted rifling is wrong.

    [/ QUOTE ]GG, again you've misquoted me. I didn't say B.J. Obermeyer came up with the idea. I said he "came up with his 5R rifling design ..." Nowhere did I say he had the original idea. There's a difference between "the idea of canted rifling" and "his 5R rifling design." Canted/angled/sloped rifling has been used for decades; check out the type used in many large caliber military barrels. Poke your head down the muzzle of one made in the early 1900's and look around. All Obermeyer did was come up with his profile; "his 5R rifling design" after testing the Russian's version.
     
  10. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bill,

    Not to give Broughton barrels a pop but remember that your comparing a little pop gun in the 6-250 to ream intense chambering in the Liljas in the 300 RUM and 270 AM.

    The longer the bullet the faster you drive them, the more fouling you will have. I have built several 6-250s on Lilja barrels and they perform the same as you report as far as fouling.

    I am sure you understand this comparision but for those that do not just wanted to point it out. /ubbthreads/images/graemlins/grin.gif

    As far as accuracy, must be the smith involved, at least with the 6-250 and 270 /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif!!!

    Kirby Allen(50)
     
  11. bailey1474

    bailey1474 <strong>SPONSOR</strong>

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    [ QUOTE ]
    The longer the bullet the faster you drive them, the more fouling you will have.

    [/ QUOTE ]

    Yeah, I understand this. I wasn't trying to bash the Liljas or anything. I love both of them!!! To be honest, I'm still not convinced that one bbl maker is better than the other.

    [ QUOTE ]
    As far as accuracy, must be the smith involved, at least with the 6-250 and 270

    [/ QUOTE ]

    It's amazing how work from a second rate smith can look good in the hands of a skilled shooter /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif!!!!
     
  12. ol mike

    ol mike Well-Known Member

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    That last sentence is way funny!

    I'll say one thing trying to figure out what barrel to get is hard.
    I guess i'll put the top names on a board close my eyes and throw a dart.
     
  13. bailey1474

    bailey1474 <strong>SPONSOR</strong>

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    Chances are you won't go wrong!!!

    Oh, Kirby, you might want to consider changing your 1/2 MOA guarantee. That 6-250 just refuses to shoot 1/2 MOA /ubbthreads/images/graemlins/wink.gif!!



    More like 1/4!!!!
     
  14. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Too-shay...... /ubbthreads/images/graemlins/grin.gif

    I would agree, with all the top end barrels, you will be hard pressed to honestly tell one is better then any other if they are broke in properly and cleaned on a regular basis.

    Good Shooting!!

    Kirby Allen(50)