Thunder@1400 yards

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by goodgrouper, Sep 4, 2006.

  1. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    I went out this weekend to double check my load in the 338 thunder and make sure it hits where it is supposed to at various ranges. I also wanted to shoot it from a bipod this time around to see how comfortable the new stock is from the prone position and to get ready for the upcoming big game season.

    I got started fairly late in the day because I thought the wind would die down a bit just before sunset. Well, it didn't until way after sunset. /ubbthreads/images/graemlins/frown.gif Luckily, I brought my wind flags and tripods so I set them up at the target and every couple hundred yards back to the 1000 yard line.

    I had to test another gun at 600 yards for group so I did that first and by the time I got around to the THunder, it was so dark that I could just barely make out the outline of the gong but I couldn't see the hits on it. THis was partly because I ran out of white paint and all I had left was yellow to cover the hits of the other gun I was testing. Yellow is much harder to see than white all the time but especially in low light conditions.

    I hurried and drove back to the 1400 yard marker and put the bipod on the thunder and quickly put the following data into my pocket pc:
    elevation 4600 feet
    temp 75
    humidity 30%

    225 accubond at 3310 with bc of .568 zeroed at 326 yards
    3 o'clock wind at 2 mph (based off wind gauge reading and wind tail positioning)

    Exbal said to dial 30.25 IPHY for ups and 1.5 IPHY for wind.
    If the bullet hit the gong, it would strike with 1287 ft/lbs and have a velocity of 1605 fps. Time of flight would be 1.80 seconds.

    Well I got the shooting pad rolled out and realized I had forgotten my hunting pack (which I practice with as my rear rest for hunting situations) back at the bench at 600 yards. So I had to use the only thing I could, my roll up foam pad. This was not the best rear rest as you can imagine. It was so bouncy that it was hard to concentrate on the target and the rest at the same time. And time was running out quick. I could just barely make out the gong by this time and could not see the hanger or the tripods of my wind flags!

    ANyway, I dialed in, relaxed and squeezed the trigger. A long second later, I saw dust which looked like a mushroom cloud from an atom bomb appear just left of my gong but it had the perfect elevation. In my haste to quickly fire before it got dark, I didn't notice the sudden increase in wind velocity my flags were telling me. Since it was so dark, I had no mirage or grass to tell me the wind situation and I simply forgot to check the flags. From looking at them now, I could tell I was back to a 6 mph 3 o'clock wind. So I dialed in another 3 IPHY's of wind, and let it rip again. This time I heard the distinct "dongg" of the bullet hitting home but I could not tell where it had hit because it was so dark. I knew however that it must have hit in the yellow part somewhere because there was nothing in the white.

    So I had four shots left and just began shooting as fast as I could get lead in the air. On the fifth shot, my wonderful foam rest gave way just as I touched the trigger and it felt like it went a mile off course. To my surprise, I still heard a "doongg". But when I went back to look through my scope at the gong, it was nowhere to be found. What the heck? THen I saw it again, then it disappeared, then it was there again! It turns out that my last shot hit on the far left side of the gong and it torqued the bailing wire on the right connecter so hard that it snapped and the gong was twirling around in the wind! /ubbthreads/images/graemlins/shocked.gif Now that is some power!

    When I was done firing, I looked at my watch and it had taken my exactly 9 minutes to lay my pad out, attach the bipod, figure my calculations, and shoot six shots at 1400 yards. Easily do-able in the field when hunting-especially if the game isn't alarmed. And you could probably throw out the time it took to attach the bi-pod because it would already be installed and rolling out a shooting mat would also be a non-issue.

    Anyhow, when I drove up to the gong, I could see in my headlights that it was a way better group than I could ever expect given the situation and bad rest. I snapped this pic with the help of the headlights. Notice the shot out far left that broke the wire.
    [​IMG]

    And here is the group in the daylight along with a pic of the new Mcmillan HTG stock which I really like. If you look real closely, you can see one of the shots just barely ticked the edge of the gong but the vertical dispersion of this group was amazing:
    [​IMG]
    [​IMG]

    Here is a pic of the 600 yard spot before it really started to get dark!
    [​IMG]

    Now it's time to start hunting!!! /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/laugh.gif
     

  2. jwp475

    jwp475 Well-Known Member

    Messages:
    2,595
    Joined:
    Feb 4, 2005
    You have her tuned in perfectly it seems............ /ubbthreads/images/graemlins/wink.gif
     

  3. sniperVLS

    sniperVLS Well-Known Member

    Messages:
    301
    Joined:
    Feb 17, 2005
    Always puts a /ubbthreads/images/graemlins/smile.gif on my face, reading your stories that is.

    Take pics of whatever the Thunder kills! Any personal records you are going for this year?
     
  4. wildcat

    wildcat Well-Known Member

    Messages:
    1,651
    Joined:
    Jul 16, 2005
    GG, what an awesome group at that range. Great story and good looking rig. Good luck hunting this year.

    Wildcat
     
  5. Eaglet

    Eaglet Well-Known Member

    Messages:
    2,779
    Joined:
    Feb 2, 2005
    GG,
    Are any of these dimensions close to reality???
    Vertical for those 3 shots would be 1.252" and largest two would give 3.229?

    [​IMG]
     
  6. skip AI

    skip AI Well-Known Member

    Messages:
    177
    Joined:
    Mar 13, 2005
    GG,
    What brand/type of bipod were you using?
    Whats your technique when firing something with so much recoil of a bipod? How do you avoid vertical stringing?

    cheers
     
  7. alremkin

    alremkin Well-Known Member

    Messages:
    89
    Joined:
    Dec 14, 2004
    Super shooting and what a great looking rifle! The only thing I can see wrong with it is that the bolt is on the wrong side, lol. /ubbthreads/images/graemlins/cool.gif
     
  8. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    [ QUOTE ]
    You have her tuned in perfectly it seems............

    [/ QUOTE ]

    Well I hope so. I've fired over 500 rounds through it so far just to make sure I've got the best equipment and load for the job it was designed to do. I don't want any surprises come hunting day!
     
  9. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    Thanks SniperVls. I try to include every detail as best I can remember because that is what is entertaining to me.

    I will be sure to have my camera with me at all times this season for sure.

    My whole intent of building this rifle was to have a 1500 to 1760 yard elk rifle so that is what I have prepared for. If a big bull appears at 80 yards then he will die at 80 yards. But if he is on the next ridge, then he will die on the next ridge. I just wanted to be 100% versatile with this rifle.
     
  10. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    Thanks Wildcat. Glad you liked it.
     
  11. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    Those numbers are almost exactly spot on. That is cool! How did you do that? Would that kind of trick work on some of these pictures of racks they claim to be 200" deer but you know it is just a 180" held close to the camera and far from the hunter?

    In all fairness, this group had a large element of luck involved. I felt I was not steady enough off my bad rest to shoot that well but I surprised myself. Especially for not knowing where my bullets were hitting on the gong. All I knew was that I was hitting it because of the sound coming back. It was 30 minutes after I shot the group that I learned just how small it was! Of course, this would not have been possible at all if it wasn't for the fact that my standard deviation on this load the day before clocked 3 fps for an 8 shot string! /ubbthreads/images/graemlins/shocked.gif
     
  12. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    I use a Harris model 25c (the swivel model).

    Actually, this rifle isn't a really bad kicker. It recoils less than my 300 win mag with a boss on it. But all I do is tighten it on real snug, pull the gun back the push it forward to stiffen the legs, and dig my toes into the sand or rocks. I use my hunting pack under the buttstock to stabilze it but always check to make sure the sling is free and not going to get hung up on anything under recoil. That is pretty well it. Fairly simple.

    The vertical stringing is mechanically eliminated in this fashion and as long as the load is good and uniform.
     
  13. goodgrouper

    goodgrouper Well-Known Member

    Messages:
    2,705
    Joined:
    Sep 3, 2004
    Thank you.

    Yes, I think 7mmrhb pointed that out as well that the bolt was on the wrong side. He says that if the doctors would have known which babies were going to be left handed, they would have drowned us at birth! /ubbthreads/images/graemlins/shocked.gif
     
  14. Guest

    Guest Guest

    Cool story. Is that hole in the top center from the infamous Lop-wah (Lapua) incident?