7mm Rem Mag or 7mm Ultra Mag???

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Topshot, Jan 8, 2010.

  1. Topshot

    Topshot Well-Known Member

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    I am looking to get a new Remington SPS Stainless rifle in either 7mm Rem Mag or 7mm Rem Ultra Mag.
    I am not worried about in barrel life as I plan to use the action for a future project anyway. I plan to shoot the 180 grain Berger bullet for large game. Which calibre should I choose?
    What sort of velocity could I expect from the 7mm RUM compared to the 7mm Rem Mag with this bullet?
    Would the 7mm RUM need a brake?
    All advice welcome
     
  2. Eaglet

    Eaglet Well-Known Member

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    On the comparing tables below, the red sections for velocities incicates the
    velocities and distances at which you are sub-sonic.

    Good Luck!

    info below on windage is for a 10 mi/hr cross wind.

    [​IMG]

    Please aproach all ammunition reloading with caution. Velocities implied may not be obtainable with your rifle. Always drop charges 10% from maximun loads and increment them slowly and carefully. You are the only one responsible for your actions. Thanks!
     
    Last edited: Jan 8, 2010

  3. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Eaglet, That's a great chart you provided for Topshot but isn't 3000 fps a little optimistic for a 180 out of a 7 RM? I was only ever able to get about 3000 fps with a 160 gr bullet out of a 24" barrel. Maybe I'm wrong, but I'm guessing 2850 or maybe 2900 for a 180 bullet out of a 26" barrel?

    Mark
     
  4. Eaglet

    Eaglet Well-Known Member

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    MontanaRifleman, you could be right, the value I used this time was not from experience since it's been a very long time I reloaded for two different 7mm RM and don't have any info. So I went to Reloaders Nest to find only one for the 180 berger and it called it for 3000 ft/sec; the other info I found after your post was on a writeup from Bryan Litz,
    I still have a gut feeling that 2900 would be better suited.
     
    Last edited: Jan 8, 2010
  5. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Eaglet, after doing a quick search through some old threads, I have seen anywhere from 2850 in 24" barrel to 3100 in a 30" barrel for the 180's. I was using IMR4350 with my load for the 160's and no doubt some of the slower powders like Retumbo and RL25 could give better performances. So My guess would be 2900-3000 out of a 26" tube,depending on powder, barrel etc.

    That being said, what really caught my attention was the MV's you used for the RM and RUM were only 250 fps diff. I figure the RUM for at least 300 fps more and up to 400 fps more depending on load etc.

    Topshot, here's and old thread that might interest you.

    http://www.longrangehunting.com/forums/f17/7mm-vs-7mm-ultra-mag-39180/

    P.S. I agree with going with the 7 RUM, especially if you're not woried about barrel life. It is an awesome cartridge. As far as a brake goes, I shoot my 300 RUM without one. The brake thing is individual preference.... If I had a 7 RUM, it would not be braked.
     
    Last edited: Jan 8, 2010
  6. Topshot

    Topshot Well-Known Member

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    Great info boys,

    The 7mm RUM is looking good. Out of the Remington Factory rifles on offer, what model would you choose, keeping in mind that I will be scrapping the rifle for its action once I burn out the tube.

    I fire a lot of rounds each year. I expect that it would take me about two years to burn a 7mm RUM barrel.
     
  7. sambo3006

    sambo3006 Well-Known Member

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    A Remington factory tube may or may not stabilize the 180 gr VLD. I have a 7mm RUM and tried the 180 gr JLK VLD. At 100 yards I was shooting a little over a half inch. I moved out to 500 yards on a large piece of cardboard and my rounds were going all over the place, around 10-12" groups. No wind to speak of and I was using a solid rest and a 6.5-20 SF Leupold, so I think human error was minimized. I was getting 3100 fps out of my 26" barrel, maybe could have gotten more but I don't know.
    The 168 gr VLD either Berger or JLK should stabilize just fine and there shouldn't be much difference in wind drift due to the higher starting velocity. Either cartridge would serve you well. The 7mm RUM does have fairly sharp recoil in a sporter weight rifle, noticeably more than the 7mm Rem Mag. Just my 2 cents.
     
  8. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Topshot, Definitely the Sendero. It has the best stock of the Rem rifles IMO, unless you dont like the HS aluminum bedded stcks. I like the older SF stocks better then the newer SF II stocks. The new ones have a wider beavertail forearm and palm swell. Maybe you might like them?

    Sambo brings up a good point about the twist and the 180 VLDs. Berger recomends a 9 and the Rem's are a 9 1/2 for the RUM and 9 1/4 for the RM. The extra velocity should make up the twist dif between the RUM and RM. There are some guys shooting the 180's out fo their factory barrels, hopefully they will chime in. I asked this question a while ago and a couple of guys ran the numbers in their quick load and said the 180's should stabilize out of the RUM, but i think we were assuming a vel of about 3300.

    Mark
     
  9. Topshot

    Topshot Well-Known Member

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    I have a Sendero SFII that was customised into my .338 Edge so am familiar with the stock but I am after a lighter rifle than the Sendero for back packing.

    I see in the 2010 Remington web site that the SPS Stainless in 7mm RUM has a twist rate of 9.25 and the Sendero has 9.5.

    What would be the minimum velocity that a 180gn Berger would expand on large game with a chest shot?
     
  10. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Berger advertises 1800 fps
     
  11. AZShooter

    AZShooter Well-Known Member

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    I got 3100 with the 180 Berger VLD from a 7 Rem Mag but the barrel is 30" long. (68 grs of RL-25 in a 1 in 7 twist, 3 groove lilja)

    Very recently I found a "like new" model 700 7 RUM in the used rack. It was an older LSS. It was produced in 1998. I also found that Rem lists two twist rates for the 7 RUM, either 1 in 9.5 or 1 in 9.25. I moly coated the bore then began shooting moly'ed 180 VLDs. I worked up to 90 grains of RL-25 with 90 grs making tiny clusters with a hint of bolt lift. I backed off to 89 grs for a velocity of 3100 fps from the 26" barrel.

    Based on my experiences with three 7 RUMs you run into pressure with the 180 VLD right around 90 grs of RL-25/3100 fps with a 26" barrel.( I checked my notes) I can't imagine how anyone could get 3250 unless they had a much longer barrel, which the 7 RUM should have IMO.

    Get the 7 RUM, don't worry about recoil, it isn't bad at all. The recent LSS was 8 3/4 lb after hollowing out the laminate stock and putting on a 4-12 leupold was very tolerable.
     
  12. signature542

    signature542 Well-Known Member

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    Good Morning, top shot.

    As you know I have the 7MM RM. I'llet you know how the new T3 shoots on Wednesday.
    The 7mm Rum is wicked but be aware my last SPS in 300 win mag after Hamsie bedded it and installed pillars would shoot nearly two touching and the 3rd opens up slightly high and to the right. Thats still pretty good from a factory stock tube!

    With the 7mm RM you can get lots of different brass including Norma quite reasonably and Ridge Rider has a good source. I'll see how the hand preped Remington cases go first and weather I am happy with my efforts.

    If your Edge is anything to go buy do you need a 7mm RUM in reality ? Light weight is the key into those back areas we go and since you have a heavy hitter and I know you have a Lilja on order will the 7mm Rem mag do it? Tough one.. I suppose you can buy one in 7mm RUM and tell us all about it! HA HA. I suppose Grey Bull and Best of the West chamber in 7mm RM for a reason.. You wont need a brake either.

    Since you will ALWAYS HAVE 2ND THOUGHTS go the 7mm RUM . Light Palma Contour DE brake and B&C vertical tactical pistol grip stock. 26inches max length
    This should weigh as much as my Accumark which is bareable covering those Valleys.

    Beside you can always make your 25/06 a 7mm
     
  13. Topshot

    Topshot Well-Known Member

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    Signature542,

    Good luck on Wednesday, the weather should be a bit cooler by then and it should be a pleasant day.

    The 7mm RUM is just such an impressive beast, I'm just gunna have to get one and run it in tandem with the .338 Edge and find out how impressive.
     
  14. linksmechanic

    linksmechanic Well-Known Member

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    I get 3000 fps with a berger 180 with retumbo out of a sendero sf11 7rm. I hope I get more than 3100 with my rum.