us869 300rum

Discussion in 'Reloading' started by model70rum, Apr 30, 2008.

  1. model70rum

    model70rum Well-Known Member

    Feb 24, 2008
    Has anyone tried us869 in there 300 ultra mags? Im thinking about trying it with the 200 grain accubonds. Is this powder to slow for this combo with a 26 inch barrel?
  2. royinidaho

    royinidaho Writers Guild

    Jan 20, 2004
    US-869 is "the" powder in my 338 RUM w/300gr SMKs.

    So, I'd think it would be well worth the try in the 300 w/the heavier bullets.

    Use the normal cautious approach and sneak up on the max load and let us know how she does.

    The load density will most likely end up being a lot less than 100 % which may indicate that 869 won't be "too" slow for the cartridge.

    Load'r up and let's see;)

  3. Derek M.

    Derek M. Well-Known Member

    Jul 12, 2004
    My best results in my 300 RUM and 200 ABs was with Re25 and Retumbo a close second. US869 is a great choice as well.
  4. mrultramag

    mrultramag Well-Known Member

    Jun 9, 2005
    I use RL25 and 200 accubond. 3150 MV and very accurate. However, I recently tried some ramshot Magnum powder w/ fed 215M, Rem Brass, 200 Accubon, oal 3.650. Preliminary indications are that 95 gr gave me great accuracy at 200yd. cloverleaf. MV was down a bit at 3100. ES was around 4. Much cleaner burning I also noticed than RL25. Food for thought. Ramshot powders are also about 5 bucks a pound cheaper than other brands here at my local Sportsmans warehouse in Oregon. Just another option to try.
  5. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

    Jun 12, 2004
    With a 200 gr AB, US869 is a bit slow in burn rate. THat certainly does not mean it will not work well. Your velocity spreads will generally be very tight because you can get very high load densities. You should also have very comfortable chamber pressures.

    Those are the good things. The bad things are that because the chamber pressure will not be terribly high for this chambering, the ball powder will likely burn pretty dirty. This is not a real issue as long as you stay on top of the carbon fouling but it can be a problem if it is allowed to build up.

    Another issue is temps change sensitivity. This powder is not the best despite of what has been claimed.

    My personal favorite powder for the 200 gr AB in the 300 RUM is Retumbo. You get good load densities, very good velocity, 3150 to 3200 fps in 26" barrels most times and accuracy has also been very good and consistant. Plus its much better for temp changes over the ball powders.

    Just what I have seen with the big 30.

    Kirby Allen(50)