New Sierra 7mm 180grn SMK's

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by SidTheKidd, Jan 24, 2011.

  1. SidTheKidd

    SidTheKidd Well-Known Member

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    Has anyone been shooting these since they came out? I am going to give them a try in my 7-300 Win Mag, since I cant ever seem to get a consistant result with the Berger VLD's.

    Today I went out and shot 2 groups with the same load using the 180 VLD's. One shot .423 at 100 yards and the other one was over a inch. I can seem to get consistant results with these bullets not matter what. I had the same problem in my 243 also, using the 105s. Soo, I decided that since I have had good luck with SMKs in the past with other guns I would give them a try in this one too.

    Just wondering how many of you out there have tried these new 180 grn 7mm SMKs. If you have, lets hear the results! Also what you were shooting them out of.
     
  2. AZShooter

    AZShooter Well-Known Member

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    SidTheKid,

    Haven't tried them yet. Sierra says they are not available, then I read that Graff's had them. Waiting for the arrival of the package.

    Sierra says a 1 in 8 twist is necessary, yet I also read that they are shorter than than the 180 VLD Bergers. I have no idea why they would suggest such a fast twist. Sierra said they made this bullet to appease the F class shooter. Yet I Doubt if many of the F class shooters have that fast a twist in their current barrels.

    I had great accuracy with the Berger 180 VLDs BUT the 3 groove 1 in 7 twist 7 rem mag began destroying 1 out of 8 after round count 225. I went to the heavier jacketed target versions and they too would occasionally get destroyed. I then moly coated and that worked for a little while. I can only hope the 180 Sierra will survive the trip.

    If they don't the rifle will be forced to shoot the bonded bullets or monos which are unaffected. Should the 180 Sierras shoot well with no chewed up bullets I'll report here.

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    Just looked at another forum and found this single report:

    As far as needing the 1-8 twist, I say no, unless some one would shoot these very slow, and I doubt that any one is shooting the 7 mm slow. I can say this from some actual shooting. I shot a ladder with the 180 Sierras at 1000yds at about 30 degrees and 700' elevation. I am shooting a 1-9, 30" 7MM SAUM, and my speeds went from 2850 to 3000. I had no signs of instability. Also I have been doing some research as to using less than 1-9 twist with the 180 bergers and found that the shorter bullets are easier to stabilize. The Sierras are about .085 shorter than the Bergers. I will soon shoot some groups based on the ladder that I shot.

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    Looks like a 1 in 9 will work fine...... wonder if Sierra will retract their suggestion for 1 in 8?
     

  3. canderson

    canderson Well-Known Member

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    I have not shot any 180 smk's, but I have shot a bunch of 180 vld out of a 1-9. My results were similar to your 100 yd testing. One group was good and then I could not duplicate it. I have several friends shooting 1-8.5 that are having a lot better results. I would err on the fast side 1-8 or 1-8.5. I would try an 8.5 with your chambering just to be safe. I was shooting 284 shehane and my friends are shooting straight 284.
     
  4. SidTheKidd

    SidTheKidd Well-Known Member

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    I found some 180 SMK's. I hope they hold up and shoot better! I will make sure i post the results for you fellas.
     
  5. roninflag

    roninflag Well-Known Member

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    i shoot 168's out of my 7mmrem mag / krieger. t he big ones are .6 i am going to try 140's next tript to the range.