new 6mm?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by midwesthunter, Dec 26, 2013.

  1. midwesthunter

    midwesthunter Well-Known Member

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    I'm looking for a new barrel for my encore and was wondering what cartridge would be best in a 26" barrel? Wanting a hot rod but don't want to be blowing un burnt powder out the end of the barrel. I plan on using for varmints and antelope out to 500 yards. Was thinking of the 6x47 lapua, 243AI, 240 weatherby or the 6x284. Heaviest bullet I was planning on shooting is 95 grain.
     
  2. lloydsmale

    lloydsmale Well-Known Member

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    probably the best bet if you want more horse power then a 6mm rem would be to have a gun chambered in 6mm06. Its basicaly the same round as the 240 wby but no belt and cheap easy to find brass.
     

  3. Gunpoor

    Gunpoor Well-Known Member

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    Any cartridge with a case larger than a 6mmRem is over-bore including a 6mm-06. If you have no issues with replacing the barrel after a rather limited number of rounds through it then the 6-284 or the 6-06 ought to do what you want. I will offer some non-solicited advise and you can reject it if you want, heavier for caliber bullets will actually hold their velocity better at longer ranges and will help reduce some of the throat erosion. If you can find a barrel with a 1/8" rate of twist you could easily stabilize 105 grain bullets and you might be able to do this with a 1/10" ROT since you are planning on using a 26" tube.
     
  4. Armored Transport

    Armored Transport Well-Known Member

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    Looking at your 500yd range use and 26" barrel I would look into the 6BR. Easiest round in the world to load for...Lapua factory brass avail. and real easy on barrels.
     
  5. RockZ

    RockZ Well-Known Member

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    I really like the 6-284! It is an awesome round. Check out the previous posts on it!
    I'm sure the 6-06 will perform well also!
     
  6. Trickymissfit

    Trickymissfit Well-Known Member

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    The 6mm Remington is indeed about all the powder the 24 bore will burn contrary to popular belief. It doesn't matter whether you go a 30" barrel a 24" barrel, the results end up being very close to each other. The .240 Weatherby case is smaller in volume than the 30-06 case used in the 6mm-06, and yet with it's higher chamber pressure shows maybe 100fps faster velocity than the generic 6mm with the help a lot of free bore. Add that same free bore into a max load from the 6mm, and you'll see similar velocity.

    The 6mm-06 has a very slight more case volume than the 6mm/284, and that round is famous for making barrel manufacturers rich. I shoot the .250 Savage case necked down to 6mm and improved. It will do 3000 fps with a little over 44 grains of H1000 and a 105 grain Amax. That's close to 150fps less than the 6mm with the same bullet, but also using about five grains less powder. But on the otherhand the better case design in the 6mm will probably give you a 50% increase in barrel life. Yet the 6mm improved case will give even better barrel life yet will be slightly overbore (not enough to be alarmed about). The .243 case is well known as a poor design, and is rather hard on barrels. Ackley did an improved version, and maybe increased the throat life 33%. Yet still way short of a standard 6mm Remington. Then we get into the 6BR that somebody mentioned here. That barrel will last 50% longer than the best of the rest with ease! It'll push that 105 grain bullet to 2800fps and some folks are getting 2900 fps; yet uses about 2/3rds the powder.

    Of course if your one of the guys that only shoots a hundred fifty rounds a year, then any of these rounds will do you just fine. The only serious difference is the cost of powder, and that still is not much. But if your thinking about a barrel life of 1500 / 2200 rounds, then you better look for a non over bore cartridge
    gary
     
  7. HARPERC

    HARPERC Well-Known Member

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    The only thing wrong with the 6mm Remington is the current brass situation.

    A lot of good choices listed, and my 2 cents is pick the one with quality brass, in good quantities readily available.
     
  8. lloydsmale

    lloydsmale Well-Known Member

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    ive got both a 240 and a 6mm rem. Loaded up to the cases show pressure signs and then backed off a full grain the 240 will beat the 6mm by an easy 200fps and with some bullets 250 fps. About the differnce between a 280 and a 7mag or a 06 and a 300 mag. If we worried about a cartridge thats over bore non of us would own a single magnum rifle or even some of the standard calibers like the 2506. The 6mm is a great round but its sure not the end of performance using a .243 bullet.
     
  9. midwesthunter

    midwesthunter Well-Known Member

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    Thanks for the responses. I'm not worried about barrel life, as here in the midwest we don't have tons of varmints to shoot, once crops are in its hard to find places to shoot ground hogs. I know the 105's will carry more speed down range past 500 and lest drift. What worries me is if I want to load some 55-70 grain bullets will a 8 twist be to fast and bullets not hold together at the higher velocities?
     
  10. RockZ

    RockZ Well-Known Member

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    My accuracy load in the 6-284 sent the 107smks down range at 3400fps.
    It was perfect for antelope !
     
  11. midwesthunter

    midwesthunter Well-Known Member

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    Thats a smoking load right there.
     
  12. Trickymissfit

    Trickymissfit Well-Known Member

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    ponder this:

    240 WBY cases are about as common as my ex wife's smile in court! The 240 will drive a 105 grain Amax to about 3250 fps max. The standard 6mm will drive the same bullet to about 3100 fps, but with about five grains less powder. Yet the 6mmAI will add another 150fps to the 3100fps and still be safe. But the other thing is that the barrel life is good. Looking thru three reloading manuals I see less than 100fps difference, but most often I find the 6mm on the anemic side. It's a true 65K psi round, and you gotta get that data. At 63K psi in the 6mm there's just not a serious lot of difference. Speer says it will do 3145 fps with a 105 grain bullet, and that's about right. I don't know how they managed that from a 22" barrel but they did. A 24" or 26" barrel will easily do that.

    Still the real issue here is hitting something at five hundred yards. The 6mm will, and it's a maybe or maybe not with the 240 and all it's free bore
    gary
     
  13. Trickymissfit

    Trickymissfit Well-Known Member

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    I shot 80 grain Sierra Blitz's all the time in a nine twist barrel with zero issues. The 85 grain is better. A ten twist barrel would be about perfect for anything under 90 grains
    gary
     
  14. Trickymissfit

    Trickymissfit Well-Known Member

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    what kind of chamber pressure?
    glt