Accuracy with 300 Win Mag.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by mgd45, Jun 30, 2008.

  1. mgd45

    mgd45 Member

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    I am currently assisting a friend who's developing handloads for a Remington XCR 300 Win Mag. We conducted a proper barrel break-in period with the standard of shoot-clean, shoot-clean for the first 20 rounds through the rifle. We were using Factory Winchester 180 grain Power Point ammo and with the the last two rounds obtained a group at .370 inches (we were also trying to sight in the scope too). We wanted more rounds before we counted that grouping but had run out of factory ammo by then.

    So next was handloads. We used Nosler 180 gr. Solid Base Ballistic Tip bullets and Reloader 22 powder. We experimented with loads from the lowest charge of 74.0 grains to the highest of 75.5 grains according to the Nosler reloading manual. We also tried an OAL from .010" off the lands to 0.025" off the lands, with the tightest group coming from an OAL of 3.587" (which was 0.010" off the lands). This group was the tightest and only measured at 1.015 ". Factory ammo had an OAL of 3.340". Factory ammo also chronoed at 3020 fps and the 74 gr. handloads were 3060 fps.....so pretty consistant.

    The owner is looking for the rifle to consistantly group at no more than 1 MOA accuracy....so obviously we were not happy with this performance. Our last thought was to load the bullets to the factory AOL and see if it can group as nicely as those last two factory rounds did when they printed at .370".

    Has anyone here experimented with a 300 Win Mag and also with heavier bullets.....? Any help would be appreciated.

    Chris.
     
  2. stxhunter

    stxhunter Well-Known Member

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    i shoot 79 gr h4831 behind a 180 accubond fed gm 215 primers oal 3.34 right at 3100fps out of a 26 inch hart barrel it will hold 1/2 moa at 500yds if i do my part, i would start out lower on the powder charge and work up
     

  3. mgd45

    mgd45 Member

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    Our rifle has a 26" factory barrel and we started at a low charge of 74.0 grains. The highest charge we've found is in the Hornady manual at 76 grains with RL22 powder. Didn't know of maybe we should experiment with heavier bullets....
     
  4. tx_shooter

    tx_shooter Member

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    I'm currently working with the 208gr AMaxes and like the results. Its a suitable target round and good hunting round for the reach of a 300 Win Mag. On a good day I can turn in a paper full of .5 moa and smaller groups. I'm working with 75grs of IMR 7828SSC and getting an average of 2925 fps MV. Next I'm going to work with my jump distance - so I'll get back with you when I find that.
     
  5. AlbertaAl

    AlbertaAl Well-Known Member

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    Feb 11, 2008
    300 Win Mag

    I've had best succes with non-magnum primers.
    H1000 with WILDCAT 190 and 210 grain bullets
    The Berger VLD 210's grain shoot great.

    The rifle is a Greywolf SAKO 75 with NXS scope

    Previusly tried bullets were the Accubond 180's, Scirroco 180 and TSX 180

    Expect more recoil with the heavy bullets!
     
  6. mgd45

    mgd45 Member

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    We were mainly starting to wonder if the rifle just didn't like the 180 gr. bullets and maybe we should try heavier ones like 200 & above....
     
  7. BigUglyMan

    BigUglyMan Well-Known Member

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    Re: 300 Win Mag

    Non-magnums eh? Interesting. I'm starting to load my newly built 300 and am just waiting for a few more bits before I get seriously into the 210 Bergers. Hard to find up here in the boons though.
     
  8. BigDaddy0381

    BigDaddy0381 Well-Known Member

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    My 300 winchester mag dosen't like 180's but it will shoot 165/168 with a 210match H4831sc perfect and then it will shoot a 200ab and a 210 berger with a F215Mag and H1000 perfect. it is strange but it's what my rifle likes.
     
  9. Midgetsniper

    Midgetsniper Well-Known Member

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    Also try 180 sierra gamekings with CCI 250 primers and reloader 22 my dads gun shoots that load very well i cant remember how much powder for sure but i think its 75 grs.
     
  10. ATH

    ATH Well-Known Member

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    200 SMK and 200 Accubonds, 74.0gr Re22 and 73.2gr respectively. CCI magnum primers. Both loads .5 MOA for the majority of groups. Factory Sendero rifle.
     
  11. grinnergetter

    grinnergetter Well-Known Member

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    Nov 21, 2007
    73 grns H4831
    fed 215 primer
    Nosler BT or Partitions 180 gn
    Lapua brass

    Stock rifle with HS stock gets about 3/4 inch at 200 yards. I gotta find a longer place to shoot:)

    Good luck, Grin
     
  12. GlennRMK

    GlennRMK Active Member

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    Jul 27, 2008
    My buddy has a Tikka T3 300 Win Mag with the 24" barrel

    I've loaded up quite a few loads for him. Probably 300 or so. There is quite a bit of freebore in this rifle. Around .100"-.200" depending on bullet(seating at mag length which is 3.365").

    We have found that the 180 Hornady SSTs with H4350 shoot the best. Very comparable with H100V. I don't have the info, but I believe I was using 69 gr H4350 with 215M primers @ 3050 fps. Pretty consistent 1/2"-3/4" groups at 100. It also likes 68 gr of H100V at the same velocity. 72 gr of AA4350 provided about 3100 fps but accuracy was about 1". Tried IMR 4831 which gave 3100 fps but about 1.5 MOA.

    His gun really likes 180 SSTs and Interlock BTSP. Tried Sierras, Barnes MRX, and Swift Scirroccos. For some reason it refuses to shoot the Swifts with every powder we have tried, over 2". This includes IMR 7828, RL22, AA4350, H100V, H4350, and IMR 4831.