7mm reloding question

Discussion in 'Reloading' started by hkm, Feb 27, 2010.

  1. hkm

    hkm New Member

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    Started to reload again and was wondering if I was using the proper equpitment. I am using a lee collet sizer and a redding comp seatting die. I have been loading some barns 160 gr tsx and some burgger 168 in a browning a bolt with a 26" kregier barel. They bougth shoot smaller that a one inch group at 100 yards. I am real intrested in improving my shooting . Thanks for any help
     
  2. Buffalobob

    Buffalobob Writers Guild

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    Do you have any kind of body die?
     

  3. Limbic

    Limbic Well-Known Member

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    I use the standard RCBS dies for my 7mag. The collet die set shaved brass off of the base of the brass instead of sizing it

    Gotta bump the shoulder back everytime

    My 168 Berger's liked to be .060 off the lands. FYI
     
  4. hkm

    hkm New Member

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    I have a RCBS full length sizer. I was also wondering if any one has any experence with Browning A bolts. I had to have mine re barreled to get it to shoot a good group.
     
  5. Bart B

    Bart B Well-Known Member

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    When my good friend used a borrowed 7 Rem. Mag. to win the big 1000 yard match at the Nationals in 1970 and set a record doing so, he used new cases or full length sized ones; I now forget. That incident caused more 7 Rem. Mag. chambered rifles to be sold than any other. Too bad that very few extremely accurate bullets were available at the time. But the ammo wasn't any different than the 30 caliber belted magnums used at the time.

    Three rules seemed to be required for best accuracy with belted magnums (rimless bottleneck cases, too, for that matter). One was to use new cases for best accuracy. Traditional full length sizing or any form of neck only sizing didn't cut the mustard.

    Another rule was that if fired cases were to be used again, they had to be full length sized in a die without an expander ball but with its neck about 2 thousandths smaller than a loaded round's neck diameter. Setting the fired case shoulder back only 2 or 3 thousandths, too. Then a second body die was used to size the case body all the way back to the belt, not 1/16th inch or so short like traditional full length sizing dies do. Innovative Technologies - Reloading Equipment now has collet dies to do this. If one doesn't get best accuracy with full length sized cases, they ain't doing it the way that works best.

    The last rule was never crimp a case mouth on cases reloaded for best accuracy. All crimping does is add another variable. It also deforms bullet jackets just enough to make 'em unbalanced when they spin at 150,000 to 200,000 rpm. All commercial match ammo as well as military match ammo for centerfire cartridges does not have crimped case mouths.
     
  6. 7mm Eclipse

    7mm Eclipse Well-Known Member

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    Bart B - Excellent response. Thanks.

    I have obtained similar results with a 7mm WSM with the good old trial and error method. I don't bump the shoulder with my reloads or completely resize my cases to exclude the 1/16th inch setting of the full length die. I will use both of these recommendations on my next batch of hand loads.

    Thanks again.
     
  7. Bart B

    Bart B Well-Known Member

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    Not that none of the standard full length sizing dies for belted cases reduce body diameters immediately in front of the belt. I mentioned this as I thought you were using a belted case.

    For rimless cases, this isn't a problem.