GS bullet range report

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by RockyMtnMT, Sep 21, 2009.

  1. RockyMtnMT

    RockyMtnMT Official LRH Sponsor

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    Hey all,

    I promised that I would report when I got out to shoot long with the GS bullets. So here goes.

    We went out yesterday, probably should have stayed home due to the weather, but we shoot so bad we went anyway. It was quite windy. Blowing around 10 to 20 mph from 2:00 on our range. Kind of a nasty buffeting, switching wind.

    We shot two different GS bullets, .264 110g out of a 6.5-06AI, and .308 177g out of 30-338Lap AI. The 6.5 is running the 110's at 3425fps, and the 30 is running the 177's at 3660fps

    We decided to shoot despite the wind just to see if the drops would match the advertised bc's. That and it is a lot of fun when you make a good shot in the wind.

    We shot out to 575yrds and both bullets held drops according to the advertised bc's. We then moved to 1038yrds. The wind proved to be too much to collect any good data. The 6.5 ran out of scope travel at the 575yrd, so next time it will be carrying a diff scope. The 30 hit the steel one out of three shots at 1038. Just too much wind.

    Not very conclusive, but I felt like we got some good answers.

    Question: What kind of effect does a head wind have on bullet flight? Reason I ask, is I was also shooting a 30-378 with 180g E-tips. It did not match drops at 1038yrds. In fact it fell very short. My experience in the past with the E-tip was good, and I did not experience larger than expected drops at long range.

    Thanks guys,

    Steve
     
  2. jmason

    jmason Well-Known Member

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    Steve- A head wind will cause more drop and a tail wind will cause less drop.
     

  3. RockyMtnMT

    RockyMtnMT Official LRH Sponsor

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    Thankyou, that is what I thought. Do you or anyone else know a formula based on speed of bullet and bc of bullet, and the wind value.

    Thanks,

    Steve

    PS I'll start another thread.
     
  4. royinidaho

    royinidaho Writers Guild

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    True statement. Is it measurable/noticeable/make any difference? Just guessing I'd think it makes very little difference..
     
  5. jmason

    jmason Well-Known Member

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    I don't have any formula but I'm sure there is one. I use software on a PDA to deal with that stuff. Bryan Litz would defiantly know it. send him a PM.

    Roy- w/ my 270 and 150 VLDs I could notice some lift from a tail wind at the last F-class I shot. .280 fan was w/ me and called a couple gusts for me that helped my score. I don't know how fast it was but when I shot during a gust I held .5 MOA low to keep it in the 10 ring.
     
  6. royinidaho

    royinidaho Writers Guild

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    You satisfied my curiosity.

    "Some Lift" sounds like about 0.5MOA @ 1K with your cartridge and load. That's more significant than I would have thought.

    Thanks
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Thanks for the report Steve. Your initial results sound great if they hold up. So you're saying the 575 yd drops are consistant with a .638 BC? That's incredible if it's true. Wil be anxiously awaiting more tests at 1K. Good job.

    -MR