300 RUM Ack Imp

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by jmden, Sep 19, 2005.

  1. jmden

    jmden Well-Known Member

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    I did a search a couple of different ways and couldn't find any info on the 300 RUM Ack Imp. If there's info on the site that someone knows about, could you point me to it?

    Does anybody shoot this? I see a PTG reamer for it at Midway apparently created by Dave at PTG. Any experiences or thoughts on performance with 180 and 200 Accubonds, barrel life and the Ack Imp idea in general on a 300 RUM?

    I know some folks say it's ridiculous to try to improve the 300 RUM case...oh well...it's fun!

    Thanks for your input.

    Jon
     
  2. 260shooter

    260shooter Well-Known Member

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    You will need a longish barrel (30") or better to be able to utilize the added powder.

    260
     

  3. Charles A

    Charles A Well-Known Member

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    Not the AI, do a search here for "300 tomahawk".
     
  4. demarpaint

    demarpaint Well-Known Member

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    The Tomahawk is the 300 Remington Ultra Mag improved, from Dave Manson reamers. 35 degree shoulder. Ray Romain out of Brockport PA has built several of them, and I believe was a big part in designing the reamer. He built mine.

    It shoots best with ball powders like H 870 (which might not be available anymore), and 220 to 240 SMK's. The ball powders are best when used in cool weather 50* and colder. Hotter weather can cause problems with ball powders. Retumbo is also a good powder for it. You can start with 300 RUM loads and slowly work up. It works best with barrels 32" and longer!

    Hope this helps,
    Frank D
     
  5. jmden

    jmden Well-Known Member

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    Hi,

    Yes, I've talked to Ray about the Tomahawk. He won't build a barrel for it under 30" for good reason.

    But I am looking for folks with experience with this 300 RUM Ack Imp. Probably the same performance as the Tomahawk, but just curious.

    Thanks.
     
  6. uncleB

    uncleB Well-Known Member

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    a RUM Ack Imp,
    Charles Emmerson Winchester III, summed this up best by stating "this is the finest ballerina in all of Galveston Texas" IE lets re-invent the wheel again and acomplish absolutely nothing.
    UB
     
  7. jmden

    jmden Well-Known Member

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    Hi, I've come up with a 300 Rum Imp idea I wanted to get some advice on (I'd better hold on...).

    Here's the specs:

    case length--2.850

    case wall--
    -base--.551
    -shoulder--.541

    shoulder--40 deg

    neck--.286

    I sent a drawing off to Dave Kiff at Pacific Tool and Gauge and he thought it would work. It's actually very similar to his 300 RUM Ack Imp.

    I'm wondering if this is too little body taper for good extraction. This is to be a hunting round and reasonable feeding is necessary. Thoughts?

    Thank you,

    Jon
     
  8. jb1000br

    jb1000br Well-Known Member

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    10 thou taper at the shoulder will probably cause you extraction probs.

    Id give her more taper.

    "ackleys" have about 10thou/inch IIRC -- that means you need over 20thou at the shoulder for it to be an "ackley"

    UncleB -- and you said i was the negative one /ubbthreads/images/graemlins/grin.gif

    JB
     
  9. jmden

    jmden Well-Known Member

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    Frank D,

    Thanks for the info. I've still got a pound of discontinued H870 left (one of the techs at Accurate Arms told me that AA8700 it's exactly the same thing, but I recorded different velocities with AA8700 than H870--maybe just a different lot)but I wasn't real impressed with it in the 300RUM with 200 Accubonds. Those were probably too light a bullet and a 26" barrel doesn't help either. Retumbo seems to have done better in my rifle with the 180's and 200 Accubonds.

    I do like the idea of the apparently longer barrel life with the ball powder (WCC 872, I think? being another one that might work well?), but am concerned about some of the stories I've heard of pressure spikes at certain temps, etc. Do you keep your rounds in a cooler if it's over 50? Most of my hunting will be well below that though.

    BTW, would you mind giving me some of your load data from the 300 Tomahawk? Bullets used, seating, powder charges, etc. How much volume did you gain over the 300RUM case with the Tomahawk? Seems to be some differences of opinion on that question so I'm curious to talk to folks that actually have a 300 Tomahawk.

    Thanks,

    Jon
     
  10. Charles A

    Charles A Well-Known Member

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    [ QUOTE ]

    BTW, would you mind giving me some of your load data from the 300 Tomahawk? Bullets used, seating, powder charges, etc. How much volume did you gain over the 300RUM case with the Tomahawk? Seems to be some differences of opinion on that question so I'm curious to talk to folks that actually have a 300 Tomahawk.

    Thanks,

    Jon

    [/ QUOTE ]

    220gr SMK

    95gr Retumbo, this is the accurate load it could go higher.

    OAL 3.85in

    About 6 grains
     
  11. lerch

    lerch <strong>SPONSOR</strong>

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    Me and Bill Bailey tried WC872 in our 300 RUM and din't get great results with it. It worked alright but when you are not loading it up pretty hot it burns like a dang coal factory and we had trouble getting enough of it in the casing.

    I haven't been shooting my 300 rum lately but Bill is having real good results with retumbo and 210gr Wildcat bullets. shooting under .5 @ 100yds.

    Good Luck
    Steve