New barrel a dissapointment.....what to do now??

Discussion in 'General Discussion' started by fnmauser, May 19, 2006.

  1. fnmauser

    fnmauser Member

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    I recently got a new "name" cut rifled barrel put on my FN mauser rifle by a top flight benchrest gunsmith.Visually the barrel and chambering look supurb. Before with the factory barrel it was a 1-1.5 MOA rifle. I've shot it and with the exact same rest/loads/mounts/scope/shooter its now a 3" for three shots rifle at 100 yards. Caliber is 30/06. Original barrel was 1-10 twist 22" ...new one is 1-11 twist 25". Load was light bullets 135-125 with moderate loads of powder, Varget, H4895. The rifle had always been a very accurate rifle so I doubt is the bedding or or mounts/scope. Action has always been glass bedded and the barrel free floated. I noticed the fired cases were sooty all the way back to the rim. All along the case. So the brass isn't sealing. Could this be the trouble? What would cause this? Its never happend before. Load was 45 grains of H 4895 behind a 125 nosler BT and 47 grains of Varget behind a Berger 135. Both loads were right at moa and the Noslers would shoot 3 into 3/4 inch at 100 with the older barrel. I'm going to try heavier bullets in it but I wanted to shoot the lighter weights. Any advice on what to try to get the groups under 2 inches at 100? Differnt primer? Bullets seated just off the lands. No pressure signs. No primer sticking out. Fired primer is flush with case head. Just puzzled at this. Thanks! FNMauser
     
  2. Buffalobob

    Buffalobob Writers Guild

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    You got no pressure. What manual gave you a load like that for H4895. Failure to seal the case neck is dangerous.
     

  3. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    I would agree, first off, you need to get some heavier bullets, at least 150 gr and I would much prefer a 165 or 175 gr class bullet.

    Then get some H-4350 or H-4831 and load then up to good working pressures. I would do this long before I give up on that new barrel.

    The loads you list are barely starting loads. Accuracy is generally not the best with this light of a load. Is there a reason you are loading such a light load? Recoil issues or something like that?

    The black powder residue on the case tells you that you are not even running enough pressure to push the case against the walls of the chamber. This means you are probably in the 40,000 to 45,000 psi range. YOu really need to be much higher then this for good consistant performance.

    Don;t give up on the barrel until you get up to normal top end working pressures with bullets at least 150 gr in weight.

    Just my opinion,

    Kirby Allen(50)
     
  4. jwp475

    jwp475 Well-Known Member

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    What Kirby and BOB said
     
  5. longtooth

    longtooth Well-Known Member

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    I agree with the others, also you might consider that just because your load worked with the old barrel it may not with the new one. Consistency is important, if everything is the same (bullet, powder, case, hold, wind, aiming point...) the bullets should go into the same hole, When you change one of these then you have a variable, and with it comes a new impact point. You made a major change with the new barrel in length, and twist. Some other variables to consider now are bedding, and barrel weight, You will have to work up another load and I bet you will find your rifle shoots fine. Good luck
     
  6. James Jones

    James Jones Well-Known Member

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    Considering the quality of that barrel , I would say that their is definatly somthing amiss with your load data..
    The only time I ever got decient results with reduces loads in the 06 was with 110gr V-maxes and H-380 , the only problem was that the velocities were inconsistant , I'm expecting due to the low powder volume.
    I'd try at least 150gr bullets.
     
  7. JD338

    JD338 Well-Known Member

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    Also keep in mind that you have to "break in" the barrel.
    I had a Hart barrel made up in 280 AI, the gunsmith told me that my groups would really tighten up after I put 200 rounds through her. After working up my load, she shoots in the .2's at 100 yds.
    Don't give up just yet. Work up some loads with some 150-165 gr BT's or SMK's and see what you get.

    JD338
     
  8. Ridge Runner

    Ridge Runner Well-Known Member

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    Hodgdon #27 lists48 gr of H4895 as the starting load for a 125 gr, your definately under pressure, I'd also go with one of the 4350 loads, or varget if you must shoot light bullets.
    JS