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.375 RUM loads

Alan RushingAlan Rushing Member Posts: 9,002 ✭✭
Do some of you folks have loads for this beast that you might share?

Have plenty of IMR 4831 and IMR 4350 available and on hand now. ( IF, something else is needed, we can go in that direction. IF, we can use my standbys or standard fare, that would be great. )

My brother will be loading several varieties of 250gr and 300gr bullets, right about now.

Any decent reload familiarity would be appreciated.

Nononsense - thank you for the post and the addendum information also, very much appreciate all of you help.


  • nononsensenononsense Member Posts: 10,933 ✭✭✭✭
    edited November -1
    Alan Rushing,

    This is where I started for some load development for a friend going to Africa.

    From the Barnes reloading manual:

    Bullet Weight: 300 gr Case Trim Length: 2.840" S.D. 0.305
    Bullet Style: TSX FB Primer: Fed GM215M B.C. 0.357
    COAL: 3.575" Barrel Length: 24"
    Case: R-P Twist Rate: 1:12"

    Ramshot Hunter (Min.) = 87.0 gr. 2605 (Max.) = 94.0gr. 2790 FPS 94% (% of fill)

    IMR 4831 (Min.) = 89.0 gr. 2597 (Max.) = 97.0 gr. 2823 FPS 107% (% of fill)



    From Hodgdon's website:

    300 SFT SP Hodgdon H1000 .375" 3.550" 103.0 2628 54,000 PSI 105.0C 2678 57,600 PSI
    300 SFT SP Hodgdon H4831 .375" 3.550" 92.0 2593 54,600 PSI 97.0 2719 62,500 PSI
    300 SFT SP Hodgdon H4350 .375" 3.550" 85.0 2598 54,400 PSI 90.0 2733 62,700 PSI

    The recipes for the H4350 and H4831sc all check very close to my results with the exception that I used the OAL of 3.600" for my chamber and feeding. There really is no significance.

    You can also use the Nosler Partition and the Hornady DGS without much difference. The Northfork Bonded generates a little more pressure so start at the beginning of the ladder for this data.

    There is very little need for a cartridge this powerful here on the NA continent unless someone wants to try for increased ranges. This is not a cartridge for the weak of shoulder, either. There is considerable recoil when the top loads are matched to the heavy bullets.

    I built a very lightweight .375 RUM for a gentleman wanting to take a lightweight plains rifle to Africa. It weighed just a pinch over 8-1/2 lbs. with the scope. After suffering a fairly decent beating, he asked me to buy it back from him. Then I built him a wonderful .375 H&H which he loves.

    I'm preparing to shoot some 330 gr. Lehigh Match bullets but we have to get after the rifling design first before I waste any bullets. Once we solve the rifling shape, we can start making some progress for a long range .375 RUM. This will be a real wind cheater if we can get it to shoot with consistency.

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