.284, 180 gr jlk's or 180 gr smk's

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by nddodd, Feb 16, 2011.

  1. nddodd

    nddodd Well-Known Member

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    Which one of these bullets would be the strongest jacket wise. I've got a 7mm stw with a 8 twist barrel and was wandering which of the two would be able to take that fast of a twist at the higher velocities.

    I'm not sure on the groove count of the barrel but I know it's a 8 twist 29".

    Any help would be appreciated,
    Nathan
     
  2. dirtball

    dirtball Well-Known Member

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    I believe they are both made from J4 jackets, but Berger makes two 7mm bullets with thick jackets if the "Hunting" version will not hold up in your rifle. They make a VLD and the Hybrid in 180gr which should hold up to anything the STW can do to it.
    Then there is always the 175gr SMK.

    Dave
     

  3. nddodd

    nddodd Well-Known Member

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    Thanks Dave, has anyone had any personal experience with these bullets that can say what speed there's blew up.

    Thanks
    Nathan
     
  4. Kevin Thomas

    Kevin Thomas Well-Known Member

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    Nathan, I believe JLK uses the J-4 Jackets, which are what Berger uses. Sierra draws their own, in house. I'm with Dave here, in the suggestion to go directly to the Berger Hunting bullets, or even their thicker Target bullets. The Target bullets are exactly the same, but made with a thicker jacket than the hunting bullets. The jackets on the Sierras are going to be virtually the same as those on the JLK design and the original Hunting design Bergers, and a bit thinner than the Berger Target bullets. Considering the twist and velocity you're looking at, I think the Target bullets would be the best choice for you here.
     
  5. rbrowne

    rbrowne Active Member

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    I shoot the 180 JLK's at 3250 out of my 7RUM. Never had any problems with them. Great bullet with great accuracy
     
  6. nddodd

    nddodd Well-Known Member

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    That's what I was wanting to hear, I just wanted to make sure they'd handle that kinda speed.

    Thanks to everyone,
    Nathan
     
  7. dirtball

    dirtball Well-Known Member

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    I tried the 180 JLK's in my 7mm Allen Mag and they came unglued at around 3300, so at 3250 you are near the ragged edge. I also have two 7mm WSM's one 32" barrel and one 21" and the JLK's shoot GREAT in both of them.

    Dave
     
  8. nddodd

    nddodd Well-Known Member

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    Hey Dave what kind of speeds were you getting out of the 7wsm with the long barrel. I've got one of those as well but it's got a 28" barrel.


    Nathan
     
  9. dirtball

    dirtball Well-Known Member

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    Just under 3100FPS, w/RL25

    Dave
     
  10. rbrowne

    rbrowne Active Member

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    Dave,

    I originnally was shooting the JLK's at 3360 and never had any issues with the bullets comming apart. I slowed down the load the load to help my barrel out a little bit while still shooting tight groups... 28" Liljia barrel, 1:8 twist, Retumbo w/Fed 215's. I will keep and eye out though.

    Thanks,
     
  11. nddodd

    nddodd Well-Known Member

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    What was your gun chambered in, if it was STW and you don't mind pm your load info with the retumbo. I know to work my way up to what you had just curious.

    Thanks
    Nathan
     
  12. rbrowne

    rbrowne Active Member

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    Nathan,

    My gun is chambered in a 7RUM. If you want that I will give it to you...
     
  13. nddodd

    nddodd Well-Known Member

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    Ahh man I was hopeing it was chambered in stw I'll be happy if I can get em to 3200 fps.

    Thanks anyway man,
    Nathan
     
  14. Rocky Mountain

    Rocky Mountain Well-Known Member

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    You dont need a 8 twist to stabilize the 180 berger or SMK, 9 twist works fine and will give you more velocity. I've tried the new 180 SMK in a 9 twist, 7mm STW, Retumbo powder, 28 inch barrel and got 3130fps with good accuracy, they have a bit thicker jacket than the 180 berger hunting bullet. I've also shot the 180 berger hunting bullet in a 9 twist 7mm RUM at 3200fps with good accuracy as well, but the hunting bergers some times stop shooting well once the throat ruff up, the j4s can be picky about barrel ruffness. The berger target bullets have thicker jackets and need to be driven fast to get any bullet expansion so not an option in the medium magnums.