2224 Yards with the LRKM

Discussion in 'Extreme Long Range Hunting & Shooting (ELR)' started by Shawn Carlock, May 5, 2012.

  1. Shawn Carlock

    Shawn Carlock Sponsor

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    A friend and I went to scout a hunting spot and test the LRKM for an upcoming rifle match at the NRA Wittington Center that will have targets from 600-2200 yards. I started at 856 yards and predictably was on the money. I was using the G1 bc's I developed for the 300 gr Berger Gen 2 out of my standard Canyon Rifle @ 2862 fps. I was sure that despite the fact that the LRKM was spitting them out at 3137 fps that all of the 3 digit shooting would probably be the same so far as BC's were concerned. The next shots I shot were at 1408 yards and again first shot hits even though I had predicted and dialed in 3.5 moa of wind. My group size at this distance for 3 rounds was about 10-12 inches using the reticule to measure.
    Our next target (rock) was at 2224 yards, have I mentioned I love my Vectronix? I ran the numbers / conditions and got 70.25 moa for elevation and 8.25 moa for a full 10 mph wind. Our target rock was large 2 moa square (4'x4' roughly) I looked at the wind gave it my best educated guess and called it 8 mph and half value, I dialed in 3.50 moa right. I stood from the rifle and looked at my hunting partner and said why don't you take the first shot? He had never shot past 1000 and was all too eager to try. He got behind my lefthanded LRKM despite being RH and settled in. I took a last look at the wind and we he was set told him to send it. At the crack of the rifle I watched the rock yawned, took a bite of my sandwich and almost 4 seconds later watched the bullet impact the rock, center for wind and about 1 moa low, not a bad first attempt for over 2K. I got behind the rifle and shot 3 shots the first being level for elevation and 8" right, the second was 8" right and 4" low, the third was 6" left and about 4" high. All in all I was impressed with the performance of the rifle to shoot a group of roughly 3/4 moa at over 2200 yards.
    There are some interesting observations in this kind of shooting:

    1. a hit of 6-8" off center is still in the group size of a perfectly centered group.

    2. every 1 mph of wind is roughly 18-19" of wind drift, so looking at my group that was very wide compared to the verticle is it capable of groups that are 8-10" at that distance assuming that the wind changes were resonsible for the remainder of the lateral group size? Or are groups shaped like that just part of the nature of spinnig projectiles and extreame distances?

    3. I was lucky to nail the wind just right on the first shot, I mean really can you tell the difference of 7 mph or 8 mph across a canyon over 2200 yards? Even looking at the difference of the wind coming from 40 degrees or 60 degrees makes alot of difference. At these distances you just cannot mess around with not being exact when it comes to the winds effects.

    4. Even though the BC's developed for the std 338 Edge were at 2860 fps or so jumping the velocity to 3137 had no apparent effect on trajectory so far as BC was concerned.

    5. It is tough but what a good time.

    [​IMG]
     
  2. Len Backus

    Len Backus Administrator Staff Member

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    Shawn, you realize the world is watching ... lightbulb
     

  3. Broz

    Broz Well-Known Member

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    Totally amazing results Shawn. Congrats to you and your friend for some great shooting and to you for creating one hell of a rifle.

    So what did you calculate the impact velocity to be? I would assume the 300 Berger had gone through subsonic transition or if not was gong through it?

    Sounds like some real fun to me.

    Thanks for sharing.

    Jeff
     
  4. BigBboy25

    BigBboy25 Well-Known Member

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    Good shooting!

    What did you calculate the BC to be?
     
  5. Shawn Carlock

    Shawn Carlock Sponsor

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    Broz,

    The impact velocity was still 1178 fps (according to the program) and subsonic happens right at 2500 yards. Of course you already know how the Berger handles reentry so to speak.:) I hope to be able to do some testing at 2500-3000 yards in near future. Based on what we saw last summer testing at 2568 I have high hopes for this setup at those distances.

    We have been using the following G1 BC's for quite sometime on the Exbal program.

    .818 lower limit 2200 fps
    .760 lower limit 1700 fps
    .680 lower limit 0 fps

    Some may not agree with them but we have used them in 3 rifles with muzzle velocities from 2600-3137 fps and they have worked very well for us.

    Len,

    I hope that there are a few people watching, I know a group of guys that are quite interested in this round, bullet and platform.
     
  6. Broz

    Broz Well-Known Member

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    Holy cow, super sonic to 2500 yards. Darn you, you are going to make me buy one of these aren't you..:) I gotta get over and get a field demonstration first though..:D

    Yes when we tested the 300's going subsonic it really didnt have much of an ill effect. Nothing like the SMK's do anyway.

    Shawn, those BC number are along the same lines as I worked out with my rifle too. Just a little spot where I had to come back up but I used 5 stepps so we are close. It is nice of you to share those numbers. I know how much work and time it takes to get them.

    Thanks!

    Jeff
     
  7. Rocky Mountain

    Rocky Mountain Well-Known Member

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    Thanks for the write up on the new toy very impressive.
     
  8. ShooterMedic

    ShooterMedic Well-Known Member

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    Shawn that is amazing, Very nice call on the wind.

    Still that is pretty Jaw dropping.
     
  9. Topshot

    Topshot Well-Known Member

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    Shawn,

    Great update and some nice shooting.
    The B.C. numbers sound accurate to me although my banded numbers are slightly different resulting in about 1.4 moa less elevation at 2200 yards.
     
  10. Shawn Carlock

    Shawn Carlock Sponsor

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    It is funny I have 3 different ballistics programs if you enter in all the same conditions etc they will all give you 3 slightly different answers. They will all work but require slight tweeking to get them dialed in to your system. Out to about 1500-1600 they are all exactly the same. I guess that was my whole point of this thread you just have to be dialed in at these ranges there is no room for error at all. It will be interesting to see how this holds up at 2500+ yards.
     
  11. Topshot

    Topshot Well-Known Member

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    Shawn,
    It is interesting how the banded B.C. numbers get much lower as the velocity reduces. My derived G1 and G7 B.C. numbers also do this but are slightly different in the lower bands.
    As I shoots at near sea level and you shoot at a much higher elevation do you think that the programs air pressure corrections could explain why we come up with a slightly different set of numbers. This is particularly obvious in the lower velocity bands.
    Given your finding with the three different programs this might be part of the reason?
     
  12. Buffalobob

    Buffalobob Writers Guild

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    If you are just a little off in the first band with either the BC or the velocity limit, then you enter the second band needing to catch up and if you do not catch up with either the BC or lower velocity limit then you are really in a major bind by the time you get to the third band.

    My personal problem is that I hate to reduce the BC low enough in the first band because I do not wish to believe that the bullet I am shooting has such a low BC. I really like to live in a fantasy land where my bullets have super high BCs. :D

    Here is a picture with the problem that I encountered when I would not lower the first band BC enough and stretched the lower velocity limit too far. Out to 1200-1300 yards I am seldom off by very much, but at the longer ranges things come unglued.
     

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  13. huntinco

    huntinco User

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    Shawn. Do you know if anyone has used doppler radar on these new Bergers yet?
     
  14. Shawn Carlock

    Shawn Carlock Sponsor

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    I am not sure but I thought Litz might have.