200 grain Wildcat's at 100 yards - next step

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by ss7mm, Jul 25, 2005.

  1. ss7mm

    ss7mm Writers Guild

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    200 grain Wildcat\'s at 100 yards - next step

    As you may know I recently tried the 200 grain Wildcat ULD RBBT’s in my 7mm Wby in a ladder test. That proved more successful than I had thought it would be so I went onto the next step.

    I went out this morning with a bunch of different loads using the 200 grain Wildcat bullets in my 7mm Wby to try for grouping at 100 yards.

    One load went into .200", one load went into 1/4", two went into 3/8" and one was 1/2". Several were in the ¾”-1” range. These were three shot groups at 100 yards. I tried 12 loads total.

    This is out of a 26” factory buggy whip barrel so I find the results quite promising.

    The .200" load averaged 2880 fps. with an ES of 15. Norma brass with all of the usual prep work, WC872 powder and Federal 215 primers. Elevation was 2770', temp was 72 degrees, barometer was 30.10 and wind was 1 mph or less. Could just tell there was a very slight breeze at times.

    I had loads up to an average of 2937 fps but they weren't as accurate. The one load that averaged 2937 was really weird because it was the only load that averaged well over 2900 and it wasn't the hottest load, by charge weight. It also had an ES of 3, but was not the most accurate load at 100 yards. I actually tried 6 loads that were hotter by charge weight. I'll give up the 50-60 fps or so in velocity to get more accuracy.

    Now I'll get some loaded up and try them at longer ranges. I will try all of the most accurate loads, including the 2937 fps load, at longer ranges because sometimes a load will do better at longer range than at 100, sometimes it will do worse. You never know until you try the combo in your gun.

    I know they work at 100 and soon I'll know if they work at longer ranges, at least in my gun.

    This is still just an experiment and I absolutely don't consider my combination anywhere near the ideal setup to be shooting these big pills. I just like doing the testing and seeing what will work, in my gun.

    Bring on the "ideal combination", the 7mm Allen Magnum and things will really get interesting.
     
  2. 7Rumloader

    7Rumloader Well-Known Member

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    ss7mm you gettin me excited about these 200 grainer's!! I got some on order now and should see them soon.
    I'm hoping for 3k fps in my Rum. How long is your tube? 26 inches?
     

  3. ss7mm

    ss7mm Writers Guild

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    7RUMloader:

    Yes it's 26" and has a Holland QD on the end in addition.

    I've got two penetration tests set up to try after the longer range shooting but I may hold off on the penetration tests until the 7mm Allen Mag arrives. Don't know if I'll be able to wait though.

    I've got up to 2937 in my 26" tube so you shouldn't have any problem getting to 3K with your RUM.
     
  4. davewilson

    davewilson Well-Known Member

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    i think you said you had a 10 twist,how much vel loss are we talkin with a 7? also was the barrel dirty after all that shootin with 872 powder and probably so cool that ice was formin /ubbthreads/images/graemlins/smile.gif
     
  5. ss7mm

    ss7mm Writers Guild

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    Dave Wilson:

    Yup - 1-10. I couldn't tell any difference after using the WC872 than say Ramshot Magnum that I use with the 169.5 Wildcats. I do think it was a little dirtier with the lower loads when I first started out with the ladder test but these are all up towards the case max + compressed and they didn't seem any different that any others. It's still a 6 patch gun with Coppermelt!!!

    As far as the barrel temp. At first I thought it was a little cooler with the 872 but I kind of got into a rythm shooting the groups and I always allow a certain amount of time for the barrel to cool. It was never more than mildly warm and the temp was 75 degrees.

    Velocity loss with a 7??? I couldn't tell you and I'll never find out because unless I re-barrel this gun at the same length I'll never know. It's not a loss I'm concerned with.
     
  6. davewilson

    davewilson Well-Known Member

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    i've always heard about the difference in velocity with a faster twist and was just curious if anyone had any numbers on this.i'm with you, it's probably a BFD type of change!
     
  7. ss7mm

    ss7mm Writers Guild

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    Dave:

    I've heard that but can't spout any numbers from experience. Kirby could probably shed some light on that though.
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Re: 200 grain Wildcat\'s at 100 yards - next step

    Dave,

    Was worried about the same thing concerning velocity loss with the 7 twist so I asked Dan Lilja flat out how much this effects velocity.

    His comment was that while it will lower velocity to some degree, it is not nearly as much as most would think. In fact variations from one barrel to another will make a bigger difference in velocity then the twist rate.

    He said big velocity drops from increasing twist rates is basically a Wives tale.

    Thats from DA MAN himself and I have never found a reason to question anything he says. He knows about 1000 times as much as I do about internel ballistics so I leave that to him and just worry about machining the barrels to shoot to their ability.

    Good Shooting!!

    Kirby Allen(50)