7mm 175gr LRAB in 7RUM

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by MMERSS, Oct 18, 2013.

  1. MMERSS

    MMERSS Well-Known Member

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    I just picked up 3 boxes of the 175 LRABs to be used in a new medium range light weight hunter 7RUM that's been sitting in my cabinet for the past month. I won't get to the gun until probably January due to HUNTING SEASON. The twist was for the 195 Bergers that never came around...8". I would appreciate any load data in the mean time for the RUM that has worked well. Of interest in addition to the most popular powders is RL-33. Any insight and help much appreciated.
     
  2. kiwi3006

    kiwi3006 Well-Known Member

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    I have got a short throated 7 RUM. I loaded the 175gr LRAB to have a 5 thou jump. Using Nosler 300 Rum brass necked down, federal 215 primer and US869 I got just over 3200 fps from them.
     

  3. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    tagging in....

    On my last 7rum I'd use I 5010 for 175's but my supply of that powder has gone bad... so far I'm working with retumbo with the 171 barnes in my current rifle but I'd like to hear about rl33 and rl50 in the 7rum of anyone has played.
     
  4. MMERSS

    MMERSS Well-Known Member

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    Load data for 7RUM with RL-33 and temperature regression

    7 RUM REM 700 action and factory Mag, 28” Lilja, 1-8”

    Nosler brass-3 shot group with LRAB 99 gr, one shot 100gr LRAB, 1 shot 101 gr LRAB, 5 shot group with Berger, Oehler 35P Chronograph

    3472 fps, 175 LRAB 101gr RL-33, .1” jump: too hot showing ejector marks, .1” too long for REM 700 Mag

    3428 fps, 175 LRAB 100gr RL-33, .2” jump, no pressure signs, OAL will fit in REM 700 Mag

    3398 fps, 175 LRAB 99gr RL-33, .2” jump no pressure signs, OAL will fit in REM 700 Mag

    3374 fps, 180 Hybrid Target, 42 degrees powder temp, 98.4gr RL-33 .2” jump, ES 34, OAL will fit in REM 700 Mag

    3390 fps, 180 Hybrid Target, 92 degrees powder temp, 98.4gr RL-33, .2” jump, ES 40, OAL will fit in REM 700 Mag

    Temperature regression with limited testing shows approximately .3 fps per degree. With a high ES and only 5 samples results indicate no validity but rather potential.
     
  5. coyotezapper

    coyotezapper Well-Known Member

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    Any further testing with this bullet / powder combo?
     
  6. MMERSS

    MMERSS Well-Known Member

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    Not with RL-33 and 175 LRABs. I settled with Berger 180s and H50 having better velocity spreads with H50.