375 Ultra build...??

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Chase Curtis, Oct 12, 2011.

  1. Chase Curtis

    Chase Curtis Official LRH Sponsor

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    considering doing a build with a 375 rum... but throating it long and setting it up to shoot the 350 smk or hybrids... 30/32" barrel...

    anyone done or herd of anything like this? I think i could get the 350 smk up to around 2800/2850 fps... some quick number crunching tells that the OAL would be around 4.120... thats at least what I would start around for the throat...
     
  2. J E Custom

    J E Custom Well-Known Member

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    If it will be a single shot any action will work . If you want to use the magazine I would recomend
    using a Weatherby MK5 action the mag length is around 3.820 and would come close to the COL
    you want. Or a custom action.

    J E CUSTOM
     

  3. Chase Curtis

    Chase Curtis Official LRH Sponsor

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    just dropping them in (single shot is fine)

    but you think the velocity will max at with barrel 32" and that seating... or call it over 4.0
     
  4. Chase Curtis

    Chase Curtis Official LRH Sponsor

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    Anyone have any info on this?
     
  5. panama

    panama Active Member

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    I built a 375 ultra for capt. M. gagllardi,Raton PD.swat team leader, used a sako action. 25" Bo clerke bbl. .700 muzzle he pushed 270.gr grand slams right at 3000fps with 92 gr. imr 4350 killed a 400 class b&c bull at 468yds. he said the bull just crossed its front legs and fell over. the throat as i recall allowed a .050 jump. and would shoot .750/3rounds @100yds. his loads, i test fired it with 89 gr. of H-1000. yes i later put a muzzle brake on it. (my design) hope this helps make up your mind. good shooting.
     
    Last edited: Oct 15, 2011
  6. Topshot

    Topshot Well-Known Member

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    I would say 2850fps with the 350gn SMK would be doable in a 30" barrel. Don't think you would need a 32 as the powder would burn quite well in a .375" barrel.
    Problem will be getting suitable bullets.
    Getting reliable B.C. numbers may be even harder as some of the custom bullet makers tend to stretch the truth with this sort of thing.
    Monilithics may be too long and you would have to have the right twist.

    I have a 32" long, 1 : 10 twist .375" barrel on order for just such a build. Not sure if it will be a .375 RUM or a Chey-Tac yet but it will be interesting.

    I plan to try the Rocky Mountain bullet first and also some home made reformed 400grain .410" Woodleigh bullets.
     
  7. Chase Curtis

    Chase Curtis Official LRH Sponsor

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    I would agree.. you might not have to go 32" but its there if needed..

    at this point I am thinking of doing it. I am leaning towards lawton 1-11 32"... I personally want to try the Rocky Mountain 370gr. As you stated though.. we will see what the real world BC is.. they claim .926... but I have some friends that say the BC on that particular bullet is correct...

    Also taking the 375 rum case and giving it a 50 degree shoulder...

    I am thinking with the 370gr.. hopefully reaching 2850/2900fps.

    HOPEFULLY...:D
     
  8. big bore al

    big bore al Well-Known Member

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    Al clark here from BC customs AKA big bore bud . I have built 338 edge with a 32 in bull barrel that is the 300 rum necked up also a standerd 338rum 29 in varment a 300 rum 32 in bull all on savage actions all with mcgowen barrels all shoot better than I can I have just placed an order for a 458 lott to shoot some barns bullets but I have been thinking of switching the order to a 375 rum 32 in tube and ream th throught to shoot the 350 smk my edge has a standerd chamder and will push the 250s well into 3200s and the 300 over 3000fps but I shooot the 250 at 3000 most of the time with good accuracy and case life would like to see 2800 out of the 375 rum set up any opinions and no spelling is not my best subject lol
     
  9. huntermncb

    huntermncb Well-Known Member

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    What about a 375-338 lapua improved