Need expert opinion on bullet Diameter

Discussion in 'Reloading' started by ShootnMathews, Apr 3, 2013.

  1. ShootnMathews

    ShootnMathews Well-Known Member

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    Here is the situation. I have a rifle that has a .310" dia. bore and I've been shooting .311" bullets in it with great accuracy. Around .3 MOA. I just recently found some bullets of the same style by another manufacturer only .312"

    Should I be able to safely shoot a .312 bullet in a .310 bore?? Would .002" really make any difference?

    I originally had no plan of changing bullets but now with the "rush" reloading stuff is getting super hard to find right now. I can't find the .311" in stock and they have the .312" bullets in stock and $10 cheaper per 100. Both bullets are HPBT 174 grn match bullets.

    Side by side picture comparrison of bullets, it appears the .312" has a shorter bearing surface and a faster taper to the point and the .311 is slightly more round coming back from the point and has "guessing from pictures" maybe 1/8" or slightly less additional bearing surface.

    Need some professional help here. Don't want to rip up my bore or face by trying to force a bullet through it that is too much difference.
     

  2. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Yes you CAN shoot over diameter by a couple of thou. in your rifle, but the pressures will be higher so you may need to re-do your load developement. In your case you are only going up .001" from your current bullets so it probably won't amount to much.
     

  3. g0rd0

    g0rd0 Well-Known Member

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    or, you could lube them with siseing lube and push then through a lee 310/1000 siser to be sure
     
  4. Sargesniper

    Sargesniper Well-Known Member

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    Hi ShootnMathews, I have a 7.7mm Arisaka that shoots the same bullet. You are OK with 312-313. ..... SEMPER FI!
     
  5. ShootnMathews

    ShootnMathews Well-Known Member

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    Thanks everyone. I figure the pressure will be about the same. It is .001" thicker but also has a shorter bearing surface. I think it will equal out. I went a head and ordered them. Ill gave to check to make sure there is room at the chamber neck to not pinch or crimp the bullet in place. That might cause pressure problems.