Results 1 to 17 of 17

Thread: 7mm RUM

  1. #1
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default 7mm RUM

    I am in the process of working up a good load for this caliber. I had always heard it was a bit finicky and this seems to have been pretty much what I have found. I want to use 160 gr bullets and have found Berger 168 gr. and Nos AB 160's with Retumbo wanting. I will be moving on to IMR 7828 and will be trying some Barnes TSX's in there somewhere. I am interested in general what other reloader's experiences have been regarding reloading for this caliber.

  2. #2
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    I'm also in the process of working up loads for my new 7MM RUM. I have a couple hundred Berger 168 gr bullets and TSX bullets in 120, 140, and 160 gr.
    As soon as my Hornady modified case arrives from Midway (so I can get a fairly accurate COAL) I'll be on my way. Several of the guys on the LongRangeHunting forum have suggested the 160 gr AB. At this point, I've only tested factory Remington 140 gr loads and my rifle didn't group these bullets very well. The first two shots from a three shot group were ok but number three was always a flyer. I've been told it's very important to give the barrel a ten minute cool-down between shots if you expect to see exceptional accuracy from the RUM. Keep us informed and I'll do the same.
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  3. #3

    Default

    You might give H1000 a try, a little faster than Retumbo and a good RUM powder which would make it a real good possibility for the 7.

  4. #4
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default

    As is often the case, my maximal COAL exceeds the magazine length so that the COAL is limited by the magazine dimensions.

  5. #5
    Member marshall's Avatar
    Join Date
    Nov 2007
    Location
    Near Phoenix, AZ
    Posts
    1,814

    Default

    For what ever it's worth I had a little trouble with Retumbo in a 300RUM, H-1000 worked better. I'm waiting to try RL-25 next. This rifle is a little picky, probably very similar to the 7mmRUM.

  6. #6

    Default

    Quote Originally Posted by shphtr View Post
    As is often the case, my maximal COAL exceeds the magazine length so that the COAL is limited by the magazine dimensions.
    A couple of possibilites here... One, you should be able to put one down as the top cartridge bullet tip will be above the mag wall. This will be my solution if I find a longer COAL is more accuruate in my 300 RUM. I'm hunt with one in the chamber kinda guy so this gives me one quick backup.... or, Wyatts extended mag.

  7. #7
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    Quote Originally Posted by shphtr View Post
    As is often the case, my maximal COAL exceeds the magazine length so that the COAL is limited by the magazine dimensions.
    I just checked what would be COAL using the Hornady OAL case gauge with the modified case. With Berger 168 gr bullet, ran out to touch the lands, the bullet base is located just inside the case mouth. This measurement isn't practical and obviously won't work. Berger's info suggests 3.600 as COAL but I can probably get by with something around 3.650 or so and still have a round that fits in the magazine. Haven't gauged the lighter Barnes bullets yet.
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  8. #8
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default

    I have been reloading for what is essentially a 300 RUM since the mid to late 90's and have had good luck with RL 25, RL 22, Magnum and IMR 7828. Retumbo and H1000 have produced less than satisfactory accuracy. Norma MRP was great....but just too hard to locate in sufficient quantity to plan on using reliably. Some of the Vit. powders also were good with 200 gr. bullets. Since I primarily mountain hunt I do not carry my rifle with a round in the chamber since to me it seems to imprudent to do so while clamoring up and down a mountain or negotiating scree/talus slides or rockey river bottoms. Despite having to load rounds so that they will fit in the magazine, I have been fortunate to find several loads that will reliably produce five shot groups into to less (sometimes much less) than my minimal 1" criteria. The 7mm RUM that I am current working on looks to be a bit more challenging.....so far.

  9. #9

    Default rl-22

    I have been loading tipped tsx 140 and 160 grain over rl-22 with great results. With these components haven't seen any finickiness you are talking about.... Also tried some winchester 150grn btsp, also shot fine. All over rl-22 though.

  10. #10
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    I finally got to shoot some test loads through the RUM yesterday. I tried 160 gr Nosler Accubonds, 160 gr Barnes TSXs, and 168 gr Berger VLDs. All loads were at midrange on the powder weight scale as I had several powders to try. The Barnes bullets grouped best which surprised me; I expected more from the VLDs. With the loads tested, H1000 was the preferred powder. I'll start running the charges up toward max now and play with COAL, however, it looks like I'm stuck with 3.670 max due to magazine length. The Barnes loads were seated for 3.580 as per the Barnes specs and all other loads were at 3.600. The best load grouped at .75" at 100 yards but I expect this to get better as I adjust the powder charge. I don't have any IMR 7828 at the moment but would like to try it later. I used H1000, H4831SC, Retumbo, and RL25. My ol' meat gun (.338 Win Mag) will shoot circles around this thing but we'll get there.
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  11. #11
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default

    Some Barnes TSX will be the next thing I try. I will be hunting in approx 0 degree weather in late Nov so am trying to utilize Retumbo for it's reported insensitivity to temp extremes. I have tried to work up loads with Retumbo in other Ultra Mag calibers without much success. The Barnes TSX have usually shot very well in the past for me so I am hopeful. To date I have sent the 168 gr Bergers and 160 gr Nos AB's down the barrel with the best results with the AB's!

  12. #12
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    My groups with Retumbo weren't anything to write home about. The best being about 1.25" at 100 yards. I believe H1000 is also considered an 'Extreme' powder. You might give it a try if the Retumbo doesn't work out. I also had a good group with the Berger 168 gr bullets using RL25. I loaded the TXS bullets up today, using H1000 and stepping up the charge starting at the midrange load I shot on Friday, on up to the max listed charge. I did the same with the VLDs using RL25. We'll see how it pans out next weekend.

    If the H1000 proves to be the best for my rifle, it will be a good thing. I have plenty on hand.

    Are you shooting a factory barrel? Seems my Remington has an extreme amount of free-bore, just something I'll have to live with. I've noticed I'm not alone with this problem.

    BTW, I find the 7 RUM to be a pleasure to shoot. I've got mine fitted with an H-S Precision stock and had the Limb Saver pad added at the factory.

    Please keep us updated on your load development. If you find something exceptional, I'll give it a try.
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  13. #13
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default

    The few times in the past I have tried H1000 I was not impressed with the accuracy, but yes, it is touted as another of the extreme powders and prob worth trying again. My rifle is a stainless Win M70 in a Rimrock stock and Lilja barrel.

  14. #14
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    I fired 36 rounds at Birchwood today. The results were not exactly what I expected. My best group was with the Berger 168 VLDs over RL25. This was shown as the maximum load in the published loading data (5/8" at 100 yards). Now I'll start messing with COAL. The COAL was 3.600 so I'll run them out to maximum magazine length and I expect the group to tighten up some. I also had a pretty good group with the Barnes TSX bullet over H1000 but the VLDs grouped better.
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  15. #15
    Member marshall's Avatar
    Join Date
    Nov 2007
    Location
    Near Phoenix, AZ
    Posts
    1,814

    Default

    Doug,

    I'm working with a 300RUM, same case for all practical purposes. I just found a very accurate load with 88.5gr of IMR-7828, 175gr Berger VLD's, Nosler brass and CCI 250's.

    I had them run out to 3.665, max magazine and worked in from there. Believe it or not they did their best at 3.555, 3/4" 3 shot groups at 200yards from a rest.

    Velocity was a touch low at 3130fps but I'll take it with this accuracy. H-4831sc was running 60fps slower with equal charges and showed craters at 88.5gr.

    I wasn't able to get my hands on any RL-25.

  16. #16
    Member Doug in Alaska's Avatar
    Join Date
    Apr 2006
    Location
    Wasilla, AK
    Posts
    417

    Default

    Quote Originally Posted by marshall View Post
    Doug,

    I wasn't able to get my hands on any RL-25.
    Marshall,

    I had the same problem with 7828, just none to be had. I shot more today and it looks like it will be the VLDs over 85 grains of RL-25. I've got the group down to about .5" at 100 yards. COAL is 3.650" which is also a little shorter than the max the magazine will allow. I'm able to run them out to 3.670 but they aren't as accurate. I really didn't feel good about them at 3.670 anyway as 3.680 is the length of the magazine. Just a little to tight in my opinion.

    Anyway, large Idaho whitetail bucks, keep your heads low after November 20! There will be thunder in them canyons!
    Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.

  17. #17
    Member shphtr's Avatar
    Join Date
    Apr 2006
    Location
    Chugiak
    Posts
    1,376

    Default

    Yea, the best powders I have found for my 300 UM's has been: RL 25, IMR 7828, Magnum, and Norma. I have got great accuracy but have serious reservations at temp's less that zero.....hopefully any velocity loss will be counter balanced by decreased air density at elevations >10K.....then, closer always works also! Good luck with the whitetails.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •