.260 Rem Barrel Twist

Discussion in '6mm, 6.5mm, and .25 Cal (Not 6BR)' started by Fullbore, Mar 31, 2019.

  1. Fullbore

    Fullbore

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    Hello everyone

    Im currently sourcing parts for a .260 Rem build off a Ultimatum U300 action I picked up on special down here is Australia. My question is the supplier I'm getting the barrel off only has Bartlein 6.5mm Heavy Palma barrels in stock with a 7.5" twist rate. Im looking to have the barrel finished off at 28". Im looking at mainly shooting the 140gr-147gr class of bullets with potentially some lighter 120-130's for hunting if I can find them cheap enough. Is a 7.5" too quick for the lighter projectiles?

    Thanks for any time and information
     
  2. Slim13

    Slim13

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    Check out the Berger rate of twist calculator. I came up with an SG around 2. Plenty of stability. Usual disclaimers about what altitude you shoot from, temps, etc apply

    FWIW when I had 260 it had an 8 twist and it stabilized 130’s and 140’s easily here in Idaho.
     
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  3. Fullbore

    Fullbore

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    Thanks for the reply mate, where I'm located I'm about 160ft or so about sea level. Im mainly worried about blowing up lighter hunting projectiles in the 7.5" twist barrel
     
  4. HTSmith

    HTSmith Silver $$ Contributor

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    I have an 8 twist that shoots 100 Gr bullets extremely well. I doubt you'd have any trouble with 120's out of a 7.5.
     
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  5. msinc

    msinc

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    You might not have trouble with a 7.5 twist blowing up jackets, but you might not get the accuracy you expect to see either. The old "everything else being equal, rifles always have the best accuracy with a twist that will just stabilize the bullet being used" is usually true. Are there some rifles that shoot acceptable with a way too fast twist??? Certainly, but from what I have seen it's the old American "if some is good then more must be better" and the guys that do it either wont admit or often make big claims, but from what I have seen their rifles don't shoot like they say. 50 grain .224" bullets fired out of a 1-in-7 twist with claims of "quarter minute at 100 yards" might take place...but I have yet to see it.
    All that said, the 260 is tricky. I believe you want a 1-in-8 for 140 or heavier bullets up to 160 grain or so. I had a 1-in-9 that shot 140's very good, but it might not have worked way out there past 400-500 yards. It was a deer rifle and not used beyond 250 or so. Go to a bullet like the Barnes TTSX and you need more twist for the weight.
     
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  6. Fullbore

    Fullbore

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    I was a bit worried about that potential loss of accuracy as you have stated. I might hold off and wait until some 8" twist barrels are available. Thanks very much for your time and information
     
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  7. muleystalker

    muleystalker Gold $$ Contributor

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    The 140gr class bullets are rockin for hunting, especially if your shooting any kind of distance. I would roll with that barrel and you would have the option of shooting the 150gr SMK's, just make sure you get a 5R barrel. Its hard to go wrong with a Bartlien barrel.
     
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  8. Rdlningcltchdmpr

    Rdlningcltchdmpr Silver $$ Contributor

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    Over spinning a bullet reduces accuracy to such a small degree that you could not measure it with dial calipers ! Krieger would be something worth waiting for.
     
    Last edited: Apr 1, 2019
  9. Dgd6mm

    Dgd6mm Silver $$ Contributor

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    I've learned this with my .260, under twist is worse for accuracy then over twist.



     
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  10. Fullbore

    Fullbore

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    Ive been looking at Bartleins this whole time but ive found a Krieger standard Palma barrel for a very good price. Is there much difference between a Bartlein and Krieger?
     
  11. FrankG

    FrankG

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    The 7.5 twist will be fine. It’s what I would recommend for the 147’s. Those will fly in a 1-8 but feel you give up a little bc.

    I don’t see you having any major problems with a 120-130gr bullets for the most part. The 120 Ballistic Tips will fly in a 1-10 twist and I’ve shot them out of 8.5 and 8 twist barrels with no issues. Going to a 7.5 again should be fine.

    I’m running a 6.75 twist on a 6.5CM and I’m shooting box 140Amax ammo, and hand loading 147 and 150gr bullets. The 140 will fly just fine out even a 8.5 twist and again in a 6.75 twist I’m not having any issues with them.

    Later, Frank
    Bartlein Barrels
     
  12. HTSmith

    HTSmith Silver $$ Contributor

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    From the horse's mouth;)
     
  13. 2506

    2506

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    Between 7 & 8 inch twist, it is a metric measurement, is what the original 96 Swedish Mauser rifles 6.5x55 have in their barrels. I shoot everything from 120 Sierra Pro Hunter which is a flat base bullet to 160 gr Sierra RN bullets with SUPER accuracy in a number of these rifles that I own. Only bullet that I did not get great accuracy from was 100 gr Sierra HP. I only tried it in one specific rifle that I had made into a sporting rifle but left the 29" barrel on it. I got flyers with this light bullet pushing it around 3100 fps. I personally believe that this bullet is too short for that twist. 120 gr Nosler BT at 2950 fps that can be achieved with AA4350 with safe pressure loads for the small ring Mauser rifle with 29" barrel is something to behold when used on white tail deer. With your modern action you can do better than that.
     
  14. FrankG

    FrankG

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    You are correct and I didn't think about that. The original spec. was like a 1-7.87 twist or somewhere around there. I know it was slightly faster than 1-8. I shot plenty of 120 SMK bullets thru a couple of Swedes that I have with no issues. My one Swede was built in 1909 and has a 29.1" barrel on it. That gun always shoots nice consistent small groups. The bulk of the bullets that have been run thru that rifle has been 120's. The hunting bullet I've used has been 140 Sierra SBT.

    The original factory military load for the 6.5x55 was like a 156gr. bullet. So the reason for the faster twist they used in the rifles.

    Current spec. for 6.5x55 Swede according to CIP is 1-8.66 twist.
     
  15. rwk

    rwk

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    No!
     
  16. jakelly

    jakelly

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    I put very little weight on the over twisting argument outside of benchrest. Another tidbit that I’ll throw in the pile; the SG required to track true through air is not sufficient to continue to track true through tissue and bone. “Over spun” bullets go straighter when the going gets tough than bullets that just meet twist stability requirements.
     
  17. Zero333

    Zero333 Silver $$ Contributor

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    Krieger is just as good as Bartlein.
    I wouldn't think twice which to get. I'd get the one that's available in the configuration you're looking for.
     
  18. JBT

    JBT Gold $$ Contributor

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    I have never noticed a difference between my Krieger and Bartlein Barrels. Both great barrels.
     
  19. Fullbore

    Fullbore

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    Thanks everyone for all the feedback, does anyone here have recommendations regarding chamber freebore? Im mainly looking to shoot 140-147gr projectiles ranging from ELD-M's, Lap Scenars and Sierra Matchkings. Would also like to have a bit of flexibility to be able to shoot 120-130gr hunting projectiles if possible.
     
  20. sbhooper

    sbhooper Silver $$ Contributor

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    If your rifle shoots the 140-47-grainers well, you really don't need to use lighter bullets for hunting. You are muddying the water. Those heavy bullets hit hard.
     
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