7mm RUM a-max problem

Discussion in 'Reloading' started by docp, Mar 13, 2010.

  1. docp

    docp New Member

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    Jan 13, 2008
    I went shooting today and decided to check my zero on a Remington 700 w/ 1-9 twist Pac-Nor 3 groove. My load is 85 gr. of Reloader 25, Fed match primer, 162 A-max bullet .020 off the lands. Conditions were: Overcast with temps in the low 50's w/ 92% humidity.
    First group 10 MOA high and 3" @ 100 yds.. This from last fall's 200 yard zero and 3/4 MOA or better groups.
    Adjusted zero 8 MOA down and shot 3 more. 3" plus.

    Started another group. 1st shot 6 MOA low. #2 OFF the target altogether! #3 was 2 FEET right and 1 foot low. Bullet tore a jagged hole in the paper.

    This barrel has less than 100 rds. down the tube.
    Bore scope shows excellent interior. Lands in great shape. Throat is fine. crown is fine. I can find nothing wrong with the rifle. Mark 4 seems to track fine. all bolts and screws torqued on scope and action.

    Could this bullet be coming apart, because that is how it is acting. I find that hard to believe, so if anyone has thoughts, I'd like to hear them.
    `
     
    Last edited: Mar 14, 2010
  2. jeffro

    jeffro Well-Known Member

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    Nov 15, 2006
    I would check your scope. Sounds like you have a scope issue. Guns dont change that much even with different loads.
     

  3. phorwath

    phorwath Well-Known Member

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    That jagged hole in the paper is a telltale sign the bullet is coming apart or not stabilizing properly.
     
  4. kiwi3006

    kiwi3006 Well-Known Member

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    Do a search on here for 3-groove barrels. I know Kirby posted up about problems he was having with 3-groove barrels tearing up bullets with thin jackets.
    You might have to try the 175 sierra match king, it should hold up better.

    Stu.
     
  5. docp

    docp New Member

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    Jan 13, 2008
    Thanks for the input. I will look into 3-groove barrels. 175 Matchkings on the way. :)
     
  6. ahuntnfool

    ahuntnfool Member

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    Mar 16, 2010
    Hi all,
    I am new to the LRH forums, but have read alot of useful info in these threads.
    I am with jeffro on the check your scope out.
    I just had a Winchester model 70 in 270 wsm with a Leupold 4-12x40 on it that did exactly what your gun is doing,and I also have a Remington model 700 sps in 300 wsm with a Burris fullfield 2 on it in 3-9x40 and it was doing the same thing.
    I took both scopes off and sent them in to the manufactures and when I got them back and put them back on..... well sub moa @ 100 yards with both guns.
     
    Last edited: Mar 16, 2010
  7. Iron Worker

    Iron Worker Well-Known Member

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    I bet your scopes are just fine. Its the thin jacketed bullets they're being ripped in the 3 grove bbl.Try a thicker skinned bullet