7mmRUM Load Info

Discussion in 'Reloading' started by Captn C, Dec 16, 2007.

  1. Captn C

    Captn C Well-Known Member

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    I just bought one and will be hand load the round.

    I would like a load for 140gr Nosler BT or 140 partition.

    I want to shoot WT deer and hogs out to 700 yard, if you think my bullet choice is to small for that range let me know. This is my first long range gun, so I need all the help I can get.

    Thanks
     
  2. speedbump

    speedbump Well-Known Member

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    Captain, a 140 might be a tad light at the longer distances, but good for mid-range. It's hard to beat a 162 AMAX and Retumbo for starters. My best luck (in a custom rig with a 1:9") is a good dose of 5010 pulldown powder & 176 or 156 Cauterucios, or the 162 AMAX. The Bergers are good bullets, as are the Sierra 168s & 175s.

    Most factory jobs have freebore that Roy Weatherby would love, seat fairly close to the lands. On a safety note, the 7mmRUM jumps from safe to HOT pressures with very little warning. Be careful working up loads and don't get locked into the velocity game - you have PLENTY to spare ! Go with the most accurate load with safe pressures.
     

  3. Captn C

    Captn C Well-Known Member

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    I know it is very easy to get caught up in the "velocity game", but I would still like it to shoot pretty flat.

    What kind of "safe" velocities with 162 gr bullets. I am a bit concerned about your comments about the caliber "jumps", so I will keep that in mind...good tip! Thanks
     
  4. davewilson

    davewilson Well-Known Member

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    180 bergers...the only way to fly.
     
  5. linksmechanic

    linksmechanic Well-Known Member

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    I'm with dave on this one. The 180 bergers are almost like a wet dream out of any 7mm. Whem jammed into the lands they cluster in the .2's out of my factory sendero sfII. I just can't say enough good about them. They carry energy and velocity way out there especially for a 7mm. I get around 2850 fps out of my 7rm.
     
  6. speedbump

    speedbump Well-Known Member

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    Captain, I haven't chrono'd the 162s, but a top end load of 176s was going @3,300fps from a 30" Kreiger over a good dose of 5010. I've downloaded that one a tad.

    As far as the Berger 180s, they're iffy from a 7mmRUM. The thin-ish jacket might not stand up to the RPMs in certain configurations. Some might, but I went with the Cauterucios since Bob uses Sierra thickness jackets that are thick and tough. They'll definitely SLAM a deer.
     
  7. Captn C

    Captn C Well-Known Member

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    Thanks for the info.

    I doubt I'll ever have a chance to do anything much over 600 yards. One of our leases is on the coast. The wind is gusting almost 24-7. It would be tough to make a shot between gusts. I guess the larger bullets help with all that. Never thought much about that.

    Thanks again.

    Any more load info is still welcome!
    I forgot to mention in the openning post: Rem 700 LSS 26" 1:9.5 all factory stock gun.
     
  8. MagMan

    MagMan Well-Known Member

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    SB, There is no explanation for it but the 180's held up much better (by comparison) than the 175 SMK's did out of a 1in7 twist I had. 7 of 10 SMK's never made it to the 100 yd target. 8 of 10 Berger 180's did. Maybe it was just coincidence.
     
  9. Captn C

    Captn C Well-Known Member

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    Are you talking about the bullet flying apart after it leaves the muzzle?

    I have heard of this in 22-250...a guy I know used to do it as joke when at the range when he would let someone shoot his Ruger #1. He swap the ammo he was using with some super hot stuff...bullet never made it to the 100 yard targets.
     
  10. MagMan

    MagMan Well-Known Member

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    Yes, The reason they came apart was because of the 7 twist. The unexplainable part is the SMK's have a thicker jacket.
     
  11. Captn C

    Captn C Well-Known Member

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    Do you think it would still be an issue with a 9.5 twist?
     
  12. linksmechanic

    linksmechanic Well-Known Member

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    No issue with 9.5 twist.
     
  13. speedbump

    speedbump Well-Known Member

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    Interesting MagMan. That's one fast twist barrel for sure. Maybe those Wildcat 200RBTs would hold up......? Linksmechanic is right - no probs with a 9.5" twist. Mine's a 9". I've seen jacket separation with a couple different 22-250 Ackleys >>>>>>>>>>>>>>> POOOOOOOOOOFFFF !!!

    I had actually looked at the 180 Bergers as soon as the 300 RUM came out. I thought, WOW, something able to push a .750BC bullet at well over 3,000 fps. I did some talking to some helpful folks, like Walt Berger, Jimmie Knox, and Bob Cauterucio, and learned more about jackets and RPMs. Walt laid the phone down for several minutes, walked upstairs, and retrieved some data on 6.5 RPMs. He concluded that the 180s were very iffy at the RPMs I expected from what was then a wildcat (the 7mmRUM hadn't been introduced) since the quality, but thin, Berger jackets might separate from the cores. Obermeyer reportedly found out the hard way in experimentation. Being the gentlman he is, Walt suggested I talk to Jimmie & Bob ... also both fine people! The 156 and 176 Cauterucios have been my go-to bullets ever since.
     
  14. MagMan

    MagMan Well-Known Member

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    They did for the first 100 rounds after that I'd be hard pressed to get two in a row out safely. It wasn't so much a poof it was more like a shotgun blast, no crack and definitely no impact.

    The 160 Accubond was the go to bullet.