What's your seating depth off the lands on the Berger 300g Hybrid OTM?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by jmden, Sep 11, 2012.

  1. jmden

    jmden Well-Known Member

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    What's your seating depth off the lands on the Berger 300g Hybrid OTM for best accuracy? I know there are a number of variables involved as to why a certain combination of components may result in a certain seating depth for best accuracy. I'm just wondering if there seems to be a consensus on a general 'sweet spot' or not. I know some have found it to be fairly insensitive to seating depth but am hoping to hear from all of you that are using it to see if there is a trend or not. Thanks for the input.
     
  2. Broz

    Broz Well-Known Member

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    300 yard accuracy was .5 moa with all depths from .015" off the lands to .060" off. .015" had a slightly better ES so I went with it.

    Jeff
     

  3. jmden

    jmden Well-Known Member

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    Jeff, Did you try nudging a little closer to the lands? If so, what happened?
     
  4. Broz

    Broz Well-Known Member

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    No I did not. I was staying back if I could find accuracy there, to keep the pressure spike down.

    Jeff
     
  5. AZShooter

    AZShooter Well-Known Member

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    I seated the 300 OTM into the rifling .010". I had ample room in the LA for the long throated 338 RCM.
    [​IMG]

    Since then I have worked up loads for the following hybrids with a jump to the rifling. All were random with OAL determined by magazine length. Only one required tweaking of the seating depth, the 284 win which liked a .025" jump.

    6mm 105 in a 6mm-284
    7mm 168 classic in a 284 win
    308 168 target in a 300 RUM
    230 target in a 300 RUM
    230 target in a 300 WSM

    I suggest you simply choose a seating depth and work up a powder charge. That may be all you will have to do.
     
  6. Broz

    Broz Well-Known Member

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    Plus 1

    .
     
  7. royinidaho

    royinidaho Writers Guild

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    I've jammed that bullet so hard into the rifling that if I didn't fire it I had to use a rod to get it out. Accuracy was out standing with 101.5 gr 50 BMG. Was great for rock bustin' but not nifty for actual hunting. Backed it in just enough to get unfired extraction. Accuracy, velocity and low ES is still there.
     
  8. jmden

    jmden Well-Known Member

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    Interesting...what chambering and what MV, Roy?
     
  9. royinidaho

    royinidaho Writers Guild

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    Factory Rem Sporter 26 inch 338 RUM;. MV = 2735 +/- 1 (usually, so far, most times, etc) Me thinks RL-50 will get a little more. Gonna try, one of these days.
     
  10. jmden

    jmden Well-Known Member

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    I shoulda realized that was the rifle you were talking about. You had very good ES in that rifle with 300 SMK's as well, didn't you?
     
  11. royinidaho

    royinidaho Writers Guild

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    Yep . . . the bergers produce a smidgen smaller groups. Not much but enough to measure.
     
  12. SidTheKidd

    SidTheKidd Well-Known Member

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    Seating my 300 OTMs .010 off the lands with my 338 Norma. Shooting 92 grains Retumbo with CCI 250s @ 2750fps. Holding .5 MOA.