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ar15 expert advice

Discussion in 'Black Rifle Forum' started by billy b, May 27, 2011.

  1. billy b

    billy b

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    i have a dpms varmit upper. 24'' heavy barrel, 1 in 9 twist. when it was new it would shoot under an inch at 200 yards. lately more like 2 inch + groups. bore does not seem to be copper fouled. upper has been shot maybe 700 or so. i need advice as to what the problem might be. i've tried cleaning barrel with everthing i have and it hasn't helped. what can i do to the upper to get it shooting good again.
     
    Last edited: May 27, 2011
  2. STI

    STI

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    Barrel crown damaged?
    Sights loose? Ammo change? Ever get the barrel real hot? Clean it with Sweets 7.62, patches come out clear?
    For that much of a difference I doubt its copper fouled that bad, but could be.
     

  3. JBnTX

    JBnTX

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    Somethings loose somewhere.
    Sights? Scope? Barrel?

    Are you using handloads?
    If so, what have have you changed?

    Rifles love handloads. That way the load can be tailored to the individual
    rifle for the best accuracy.

    Don't over clean it!
    You'll do more damage than good.

    Maybe it's just a bad barrel?

    Sweets 7.62 is POWERFUL stuff. Use it sparingly and don't leave
    it in the barrel for an extended period of time.

    Only the worst of fowled barrels with thousands of rounds should be exposed to
    Sweets 7.62 solvent. With only 700 rounds fired I'd refrain from using Sweets 7.62.

    Believe it or not, you can destroy a barrel very quickly by over cleaning.
     
    Last edited: May 27, 2011
  4. Randy from Kansas

    Randy from Kansas

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    Every thing that has been stated above, plus bags, bench, wind and mirage.

    Under an inch at 200 yards is a very good group was it 3 shot or 5 shot. Could you repeat it several times in a row or did you get one 7/8 group and 2 more at an inch plus.

    Really need more information,

    I was shooting my 24inch Colt A3 this afternoon at 100yds and had a couple under 1/2 with hand loads. I am trying to find the right combination of powder bullet and OAL for best groups. Here is a picture I took
     
  5. billy b

    billy b

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    barrel is stainless. shooting same reloads as when it was new.50 grain nosler bt, h335. mounts are tight, warne rings. friday i put 3 shots in same hole at 200 yarda. next 2 groups 2 inch + again. i shot my bushmaster same day and shot it great. so i know my ability to shoot is still good. scope is a sightron 6x24.
     
  6. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

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    The "three shots in the same hole" grouping, was this the first grouping?
    Clean bore?
     
  7. Randy from Kansas

    Randy from Kansas

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    On the last two groups over 2 inch did it place them vertical or horizontal. Horizontal would tell me wind, and vertical could be mirage.

    What type scope do you have on your Bushmaster? Can they be placed on your DPMS?
     
  8. AK_Stick

    AK_Stick AAAMAD

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    Solvent, will not hurt the steel of the barrel.

    Now, you can do some serious damage with a improper use of a brush or jag or whatever, but the solvent is not going to affect the steel in the slightest.
     
  9. billy b

    billy b

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    3 in one hole was the first or second group out of a clean barrel. next four or five groups were just scatered, no horozontal or veritical stringing. i allowed barrel to cool between groups. bushmaster has a nikon 6x18 on it. truth is i have bushmaster shooting great. it shoots 1 1/4 groups at 200 yards. i hate to have to mess with it. i do have a bushnell 4x12, but i don't think it's enough scope.
     
  10. BBJones

    BBJones

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    10 shot groups would be more meaningful. 3 shot groups introduce all kinds of statistical anomalies. Even 5 shot groups would tell you more.
     
  11. thisaway

    thisaway Moderator

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    Sweet's 7.62 contains a high percentage of ammonia, which will damage the barrel steel if left in the bore for a long period of time.
     
  12. AK_Stick

    AK_Stick AAAMAD

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    I really, really doubt it.

    Ammonia is used to clean guns after corrosive ammo has been fired, and black powder guns. While it can be bad for the stock, and can cause surface rust, which will require more cleaning later, I'm really not buying it's going to hurt the bore.