7 WSM or 7RM

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Ksmirk, Mar 31, 2008.

  1. Ksmirk

    Ksmirk Well-Known Member

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    Ok folks I've been beating this dang thing around for a long time and I have gotten many different reports! imagine that huh? What I am looking to do is put the hurt on a steel plate at 1760 yards! simple not going to be hunting with the rifle if so it might be some of these little Okie deer and I'm sure a p-dog, I have been told everything from 50BMG, 338 Edge (I still want this one!) and a 7WSM my thing is crunching the data it looks like the 7WSM will go subsonic before it gets to 1760 with a 180 Berger so what would be wrong with just going with a 7RM? looks like it should stay supersonic well past the 1760. I ask you guys cause there are a few of ya that know what would work out so I'm asking what you think?

    This will be on a Savage action so I'll have the Edge but not right now, need to have easy access to brass, does not take a pound of powder, something the everyday Joe can afford to shoot if that makes sense? Later,

    Kirk
     
  2. britz

    britz Well-Known Member

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    I'm no expert on either cartidge, but I did some searching on hodgon's site and it seems both the rem mag and the wsm have very similar performances and neither would have the advantage. BUT, the WSM in a short action would have a major disadvantage because you would be forced to use up much case capacity. However, I think you would also be seating the rem mag fairly deep too. Just on basis of theory, I'd look into doing a WSM on a long action designed to seat far far out of the case with the 180's. According to the reloading info, You should be able to get close to if not past 2800 fps and JBM calc says it will stay supersonic to just past 1 mile with a VLD berger 180.
     

  3. topwater225

    topwater225 Well-Known Member

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    Here is my take....FWIW
    First of all Do you mean the 7 RUM?
    The RM is going to give you the same (basically) performance as the WSM. The RM will not be supersonic any longer than the WSM.

    Go WSM with short action. If this is a custom job, you can get a box that will allow you seat the bullets out as far as you need with the 175’s and you may have to shoot single shot with the 180 Berger. Not a big deal when you’re shooting steel.
     
  4. Ksmirk

    Ksmirk Well-Known Member

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    Yes Remington Mag, this is going to be done on a long action! I did my 243 on a long action and with the 105's it helps get a bit more powder in the case as we set it up for the 105's set out there long. I'm going with a long action Savage action so I can swap out the barrel when I get used to shooting at those ranges I'll swap out the barrel for an Edge more than likely. Later,

    Kirk
     
  5. P KUNDA

    P KUNDA Well-Known Member

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    The useful case volume capacity

    Is everything. If everything else is equal the useful case volume capacity will always win.

    Peter
     
  6. landcbeitner

    landcbeitner Well-Known Member

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    Yes "all else being equal" but, I believe the WSM's operate at higher case pressures. According to Sierra's reloading manual the RM should have a slight advantage with the heavy 7mm bullets.
     
  7. Buffalobob

    Buffalobob Writers Guild

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    The guy is shooting at a mile!!! For goodness sakes he ain't asking for a belt feed rifle. I simply can't fathom the need for a magazine. You can reload a single shot three times before the first bullet even lands.

    A 240 Wby with a Berger 115 and two and a third dump trucks of RL22 in the case will make a mile. You would not want to be standing there when it landed.

    A 257 Wby with a Wildcat 142 RBBT will smoke a mile and give you nine cents change.

    What you need is a launch speed of about 3300 fps and a BC of 0.6 . If you go to a higher BC you can go to a lower launch speed. If you go to a larger bore diameter then you can prolong barrel life. Go play on JBM and find what gets you what you need with the least launch speed and largest diameter. Remember Richard Graves makes some great bullets.

    Other option is to select a gunsmith who knows which end of the bullet needs to land first at a mile and ask him and have him build it. Both Kirby and Shawn knows. If you think that is a stupid comment then I can dig in the trash for a bullet my son found at the F-class match that had landed backend -forward.

    I do not recommend either the 240 Wby or the 257 Wby to you for what you want as these are cartridges for killing animals at long range not shooting steel plates. I have my heat up the barrel paper shooting" rifle and then I have my "very carefully pampered hunting" rifles.

    Hopefully, this has help you get a grip on the small caliber range and then you can work on the larger calibers.
     
  8. Ksmirk

    Ksmirk Well-Known Member

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    Ya my 243 with those 105's smokes the hell out of my 308 so I know those little guys can get there and much easier than the big guns in most cases. I was told that with the powder charge I'd be better off going nothing under .284 or I should order 2 barrels at the same time! so this is part of the reason I'm looking at the 7mm wsm, saum, rm, cases pretty easy to get ahold of and I'd not need to get that CDL for the dump truck ;-)

    Yep I know about those @$$ backward bullets! my 308 I set up to shoot the 155 palma bullets so it's got a 1-14 twist barrel, the 168's do good out to a little over 800 yards then you get about 2 of 10 that make funny holes. Later,

    Kirk
     
  9. uncleB

    uncleB Well-Known Member

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    britz is spot on with this, I have a 7WSM built on a long Sako AV action with a long throat so that a 180 Berger has only the boat tail below the neck, my best load had a adv. velocity of 2861 and a s.d. of 4
    this rifle was previously a 7RM with a factory tube that would not even come close to this.
    UB
     
  10. linksmechanic

    linksmechanic Well-Known Member

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    I would go with the Rm with the berger 180. I get better velocity with the Rm compared to the wsm and it seems I can find brass alot easier and cheaper.
     
  11. Ksmirk

    Ksmirk Well-Known Member

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    So it sounds like either would be a good choice? granted I would have thought the 7RM would do better with the bigger bullets due to case volume being a bit larger. I did some looking around and it seems that the 7RM will push the 180 a bit faster but I did not see a wealth of info on the 7WSM with heavy bullets! being I have access to the reamer and know the guy that will be doing the chamber I can set either up how I want it prob have to go single shot with the 7RM but those steel plates don't run all that fast if a follow up is needed ;-) Thanks fella's! Later,

    Kirk
     
  12. linksmechanic

    linksmechanic Well-Known Member

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    I seat my bullets to the lands with the rm and have no problems with them touching in the mag and that's on a stock 700.
     
  13. IChaseCoues

    IChaseCoues Well-Known Member

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    According to my ballistic program, my 7WSM is supersonic to 2000yds.
    Here's the data,
    7WSM
    Berger 180 VLD BC .684
    2895fps 10 ft from muzzle

    Tats at 4500ft ASL.
    I don't know your altitude, but if I drop it to 100ft ASL, it goes subsonic right at 1760.

    My $.02.
     
  14. tjonh2001

    tjonh2001 Well-Known Member

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    i actually shoot a 7mm wsm. the gun that i am talking about was a 7mm remington mag, in a sendero. i have changed it to a wsm and many more mods. the wsm needs to be built on a long action so that you can seat the bullet out far enough. as far as that i have a load for my berger 180s launched at 31oo fps. 1800 ft and 60 degrees. it still has1292 fps at 1760 yards. so it can shoot the mile.