Is 9 twist satisfactory for the 195 EOL?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Max Heat, Aug 20, 2013.

  1. Max Heat

    Max Heat Well-Known Member

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    I have a 32" RUM bbl on order, and my choices were 8, 9, and 10. Since I am currently the shooter of relatively light bullets (140 Super Shock Tip), I didn't go with the 8 twist. But with this heavyweight making so many waves, claiming to be the "king of the mountain", in terms of slipperyness, I'm having a hard time ignoring it. Especially being that it IS in MY caliber. Any ideas on how tight the groups would be at say 600yd, compared to the 140 SSTs? I'm very generous with the amount of powder that goes into the cases.
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    My Sendero SF has a 9.25" twist and it shoots 180's fine.

    From my experiences I can't see why it wouldn't work...
     

  3. Edd

    Edd Well-Known Member

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    Berger recommended a minimum twist of 8.5".
     
  4. Broz

    Broz Well-Known Member

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    My guess is you could get away with it above 4000 ft asl. with a 9 twist. But for the 195's a 8.5 or faster is recommended and will most likely be needed for the best accuracy.

    A 140 and a "generous amount of powder" in a 7 RUM ? Better have the smith fit a spare barrel or two while he is at it.

    Jeff
     
  5. Elkhunter1983

    Elkhunter1983 Well-Known Member

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    Isn't this all speculation along with the boogey man and elvis at this point or are these things actually scheduled to get made in the foreseeable future?
     
  6. MMERSS

    MMERSS Well-Known Member

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    I'm speculating you may burn your 9 twist up long before the 195s hit the market. Shoot the 180's in the meantime if you crave a heavy hitter. They should shoot great in a 9 twist RUM.
     
  7. Max Heat

    Max Heat Well-Known Member

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    So 8.5 is "recommended" minimum? All that means is that they won't shoot "ideally" with 9. But I didn't realize they aren't actually even out there yet. So then, nobody has even shot any yet, to be able to say? It looks like that answers the question for now.

    In case you couldn't guess, I'm actually a velocity-craver by nature. You just can't help but admire the kind of performance numbers which that round represents though. Just like with Porsche (well, sort of), there "literally" IS NO SUBSTITUTE for numbers like that. Not in 7mm, anyways.

    FYI - I refer to my solution to fighting barrel burn as the "mom" treatment. It's an acronym for moly-on-moly, meaning that moly-coated bullets are shot though a moly-coated bore. It's really too early to say how well it is workng at this point, as I haven't been doing it for very long yet. But the more I do it, the closer I seem to be getting to becoming a dedicated believer in the process.
     
  8. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Yup, Why go from 140's to the 195?

    Twist and SD will tell you something about the BC of a bullet. If a 7mm cup and core bullet weighing 195 gr stabilizes in a 9 twist, I would seriously question the BC advantage over the 180.
     
  9. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Why are you getting a 32" 7 RUM for 600 yd shooting? If your looking for accuracy @ 600 yds, use something like a 7-08 or 7 x 57 shooting something like a 168 Match VLD Target in a 10 twist. The 7 RUM will be more finicky to develop an accurate load. As to which bullet, Horandy vs Berger, is more accurate, no one can tell you that. Every rifle and barrel has its own personality. A well built rifle with a good custom match grade barrel should shoot most anything well.

    What's your priority? You ask what's more accurate... the SST or the EOL? Then you balk at the "recommended minimum" twist for the big bullet? There is a huge diff between the 140 nd 195 bullets. For best results you need to decide if you want to go heavy or light. The 7 RUM is an inefficient chambering and extremely inefficient with light bullets. It will push bullets faster than most other chamberings, but at a great cost.

    Moly was the voodoo craze years ago but now a days everyone has abandoned it, but hey, it your $$$$$.
     
  10. MudRunner2005

    MudRunner2005 Well-Known Member

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    I'm impressed, normally during a 7mm conversation, I would expect to see more negativity from Mark....:D

    But, in this case, I believe he is 100% spot-on with everything he's said. :cool:

    Basically, what the OP needs for 600 yard shooting and hunting is a regular old 7mm RemMag.

    There's guy's who have killed 1,200lb moose @ 1K with a 7mm RemMag, yet most folks underestimated it completely.
     
  11. Dick Tinsley

    Dick Tinsley Well-Known Member

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    Got to 2nd that!!!!!! Couldn't have said it better!!!

    DT
     
  12. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Contrary to what you think, I have no dislike for the 7mm. I don't don't dislike any cal. I would like to have at least one of everything and I just about do.

    Now when you're talking about LR hunting, I will always say that bigger is better. A 6.5 - 284 is better than a 243, a 270 WSM is better than a 6.5 - 284, a 7 RM is better than a 270 WSM, a 300 Mag is better than a 7 Mag, a big 338 is better than a 300 mag, a 375 CheyTac is better than a big 338.

    If the OP is hunting @ 600 yds, then I agree, a 7 Mag would be good. But he did not mention hunting so I think for target shooting he would be more likely to see better accuracy with one of the lighter chamberings. My smith is a 7 lover and he shoots a 7x57 wildcat of his own design in LR tactical type competitions and he has taken home a lot of trophies. He also says the other cartridges you probably see most often in the winners circle are 6.5 x 47's and and 260 Rems. He thinks that the magnum chamberings are more finicky for accuracy and he is probably right. I think he thinks I'm a bit eccentric with my overbore obsession and he's probably right again :)

    To the OP, I would love to have a 7 RUM, but man they are hard on barrels. When you get your RUM, shoot heavy bullets out of it to get the most out of the cartridge.... and the barrel. The only thing i would even think about shooting out of a RUM is the 180's and if the 195's where availble they would be my top choice.... provided their BC was that much better than the 180's. As for twist, get the tighter twist optimum twist for the 195's if you think you're going to shoot them. It's better to have more twist than you need than not to have enough.
     
  13. MudRunner2005

    MudRunner2005 Well-Known Member

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    I have to agree with everything said, except the bigger bore is always better for LR.....But that's all a personal preferance, whether facts are facts, or not.

    With a precision shot, anything can be deadly, but sometimes I do agree that more powder capacity does make things more fun. For example, I love my 7mm STW. Fun to shoot, and it pushes the heavies REALLY efficiently compared to my 7RM. Also, the .22 caliber wildcat I'm working on will be really nasty, and probably not so great on barrel life, but it will be fun while it lasts, and will probably be one wicked coyote killer.
     
  14. Dick Tinsley

    Dick Tinsley Well-Known Member

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    I too agree with everything on this tread! I do own different caibers. I chose the 7mm mag, because I just like it!! That being said, that's why different people like different calibers! Just my 2cts is like MontanaRifleman said, goin from 140's to 195's is a big jump!! Whew! I also agree with Broz. Berger recommend at least 1n8.5 with the 195's. I personally don't have any experience with anything bigger than a 180 in a 284 caliber an it works in one of my 7mag's. the other one don't like em. But then again, differant guns shoot differant bullets! If I did own a 7 rum( I've owned 2) the smallest I would shoot would be a 168grn. If the OP wants to shoot the 195's, IMO I would get at least a 1n8.5 twist. That's a lot of bullet for a 284! Just my 2cts!

    DT