Retumbo in 300 Ultra

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Charter, Mar 7, 2003.

  1. Charter

    Charter Member

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    Feb 21, 2003
    Has anyone tried the Retumbo powder in the 300 Ultra. The listed valued for a 180 gr. Speer SPBT are (MAX) 100.5 at a velocity of 3300 out of a 24" barrel with 62,300psi. My 300 has a 26", should I expect 3350-3400 fps?
    The bullet has a BC of .540 so it should carry pretty well. I am considering using this for hunting, but am concerned about the bullet not holding together at the close range velocities.

    Let me know what you think.

    Than
     
  2. Boyd Heaton

    Boyd Heaton Well-Known Member

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    May 14, 2001
    RL25 is THE powder for the 180gr bullet's.Retumbo does not start to come into it's own until the 220 and 240gr bullet's are used...I have safely gotten 3410 with the 178 a-max and rl25 in a 26" barrel
     
  3. Huntaholic

    Huntaholic Active Member

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    Jan 13, 2003
    Ive been playing around with it some in my 300 ultra. I have yet to find that magic load though, most groups run around an inch. So far Ive tried the 200 SMK and 180 sierra SBT bullets.
     
  4. BountyHunter

    BountyHunter Writers Guild

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    Dave

    try Norma MRP2, sold by one distributor, Graf and Sons. It is equivalent to RL25, much more consistent from lot to lot.

    BH
     
  5. djdcsi

    djdcsi Well-Known Member

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    May 19, 2001
    Roger that, Boyd. In several different calibers, my experiance thus far is I reach pressure before the velocity I am expecting. Staying with Rel-25 for now but searching hard for a replacement, since it varies so much from lot to lot and is temp. finicky.