Is this hard on an AR15?

Discussion in 'AR15/10 Rifles' started by kc, Jan 20, 2012.

  1. kc

    kc Well-Known Member

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    Can the AR 15s take the punishing recoil of the .308 and could you see into the future this
    rifle shootind short Magnums?
     
  2. James H

    James H Well-Known Member

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    A 308 Win. will not fit in an AR15. Dedicated Technology and Olympic arms make AR 15 uppers in Win Super Short magnums. James
     

  3. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    Good point.

    You need a 308 pattern AR platform. There are alot of good ones and some not so good out there. There is no standardazition with the larger AR rifles. Here are some ideas that will fit in an AR15. 6.8spc, 6.5 Greandel/LBC, 30AR, 6mmturbo, any of the wssm lin up. this is just a few.
     
  4. midwesthunter

    midwesthunter Well-Known Member

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    To add to this dedicated tech uses a heavier duty billet upper and a lot stronger bolt carrier. If I was to get one of those get the billet lower from them to match.
     
  5. brentc

    brentc Well-Known Member

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    There are SAUM chambers on the AR10 platform.
     
  6. REDHEAD

    REDHEAD Well-Known Member

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    Ok , if I have a standard AR platform and I purchase a 6.8 spc upper - does anything need to be done with the recoil buffer ? 450 , 6.5 ?
     
  7. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    You "might" need a heavy one like an H2 its better to ask the manufacture.
     
  8. LouBoyd

    LouBoyd Well-Known Member

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    The purpose of the spring and buffer in an AR-15 is not to control recoil. Their function is to control the velocity of the bolt carrier and to store energy during the extraction, ejection, cocking the hammer, (and locking open on the last round) and to return that stored energy at a controlled rate to strip the next round off the magazine, chamber the round and lock the bolt. How powerful the cartridge was makes almost no difference since the barrel designer will give the gas port the correct position and diameter to give the correct gas impulse to the bolt carrier. Unless you're cutting your own barrels or using very non-standard loads you don't have to worry about it. The buffer and spring have a small effect on felt recoil, but felt recoil should be controlled with a muzzle brake, shoulder pad, by added weight, or usually just ignoring it.

    Messing with the spring rate and buffer weight can "tune" an AR-15's timing, but that is rarely needed or desirable.
    I have AR-15 uppers in many cartridges including 6.5 Grendel, 458 SOCOM, 50 Beowulf, and 300 OSSM (necked up 25 WSSM) and they all use standard lowers with standard springs and buffers (some rifle and some carbine). My 300 WSSM has a Stag 223 marked lower with a standard 223 buffer & spring and it works just find. The only special parts in a 300 WSSM are the barrel, the barrel extension, and the bolt which are larger both for strength and to fit the case head. The bolt carrier is standard. The only thing special about the upper receiver is the ejection port has been widened.

    Even 50BMG single shot uppers don't put exceptional force on an AR-15 lower unless you restrain the lower against some solid object. A human shoulder is not a solid object.
     
    Last edited: Jan 29, 2012
  9. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    Thats a good explanation but its important to note that optimal bolt speed varys with barrel length and reciver extension choice. There are diffrent buffer weights for a reason. It will all depend on the configuration of your rifle there is not "standard buffer" and spring length for the AR system over all. There are mil standards for the M4, Mk18 and M16.

    I have to find it but there is a chart that explains it all I'm looking now