Drop Test ....

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 41mag, Jul 28, 2006.

  1. 41mag

    41mag Well-Known Member

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    I wil be hopefully squeezing off the first round as soon as I can see the 500yd plate in the morning. Temps should be in the mid 70's and hopefully no fog. Once I verify the zero, then I will shoot at a target mounted to a fixed position on a tall board frame from there on out.

    My coheart in crime and I got the 270 AM shooting pretty well last trip out at 200 yds., after a little seating work. I plan to adjust the scope to zero at 500 and then go from there, since I only have a limited number of rounds left of the bunch. I should be able to shoot three shots each at one hundered yard intervals out to 1000 yds, and if things work out possibly even a little further.

    Will this be enough to represent a valid test, or will I need to have more shots per range? I figure that with the temps being what they are around here, and the mirage as well, that we will only have about 2 hours of good conditions to get this done in. I realize that practice is always the key element, but this time I have to make the most of the time I have and keep things moving.

    Any ideas or suggestions are more than appreciated.
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Mike,

    THat will give you a hell of a start of developing and tweaking your drop chart to match your actual bullet trajectory.

    As the fall temps roll in you will need to do a bit more tweaking but this test will get you alot of information quickly.

    I generally do not shoot every 100 yards out to 1000 yards. Its fine if you do but in my opinion not needed. To accurately plot your bullet drop I like five pieces of data:

    -Scope to bore height
    -Muzzle velocity
    -200 yard impact height
    -600 yard impact height
    -1000 yard impact height

    If you have those numbers and your ballistic program can be tweaked to match or come VERY close to all the drop numbers in your shooting area, you will have a very accurate drop chart.

    Two down range impacts can work but three is vastly superior as far as accurately predicting your bullet drop inbetween those known ranges.

    Again, more ranges does offer more data but if your drop chart matches up to three different down range numbers then it will more then likely match up with everything else inbetween as well.

    Just my opinion. I do things quite simply. Perhaps to simple for some but it does work.

    Let us know what results you get!!

    Kirby Allen(50)
     

  3. 41mag

    41mag Well-Known Member

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    I had a little time this evening to prep up a few more loads. SO I am good for some real shooting. We have an appointment to keep tomorrow at 10 so I decided to forgo the early morning shoot tomorrow and get the meeting stuff overwith and done. That will give us the rest of the evening to get things lined up and ready for a Sunday morning shoot. The weather is calling for possible early showers tomorrow as well.

    As far as fall temps, LOL that will more than likly not be until around Janurary here. Shoot it isn't uncommon to be in the mid to high 80's mid December. I figure that I will have to adjust it some during the course, but by then, we will hopefully have the both of them up and running so things should be fairly easy.

    It's just hard to drop everything week after week and head up there just to shoot. There is so much other stuff to get done that the shooting, generally takes a back door, and then you have to fight the effects of the wind and heat.

    I will definatley post up what comes of it, and I hope you and that northern'er have had a good time. Sure looks like it.
     
  4. lerch

    lerch <strong>SPONSOR</strong>

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    Mike you got rain chances down there??? Who's butt did you kiss, we live in the Sahara up here!!! Temps today hit 102 and I am dying to test the new 195gr 277 this weekend, forecast shows 105 every day for a week!!!

    i know what you are talking about with december temps in the 80's. My biggest buck died in november on a morning that started out at 40deg and when I field dressed him I did it in a t-shirt and boxers and boots at what had to be 80deg!!! must have been a funny sight seeing a 6'5" guy in his underwear have covered in blood, actually that might have been kinda scary. /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/grin.gif

    Good luck shooting the 270AM. As soon as we get some more 195's in I will send you a little present!!!!

    take it easy
    steve
     
  5. 41mag

    41mag Well-Known Member

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    Lerch,

    Thats what they mentioned on the weather report last night, here is the NWS forcast for where we will be, from this morning,

    Point Forecast: Crockett, TX
    31.27N -95.4W

    Today: Partly cloudy, with a high around 95. Heat index values as high as 104. South wind between 5 and 10 mph.

    Tonight: Partly cloudy, with a low around 74. South wind between 5 and 10 mph.

    Sunday: A 20 percent chance of showers and thunderstorms after 1pm. Partly cloudy, with a high near 95. Heat index values as high as 104. South wind between 5 and 10 mph.

    Sounds familiar huh, LOL I would be willing to bet it hits higher than the predicted temps as well. OF course down here on the coast, it has rained a little every day up till yesterday. Yesterday the sun was out in force along with the humidity. Lots of fun I gar'an'teee./ubbthreads/images/graemlins/grin.gif

    Might just have top rig up some lights and go at it after dark. We'll see how it goes.

    Just let me know if something is headed this way, so I can prep up some good cases. I wouldn't want to use up something new in the worn ones. /ubbthreads/images/graemlins/grin.gif
     
  6. royinidaho

    royinidaho Writers Guild

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    Mike/TX,

    My experience when shooting with the target lighted @ night was that mirage was way wierd! I tho't my rifle broke. Really! Don't know what your neighborhood is like but up here it wasn't worth it.

    I ran a test one morining with my 40X 222 w/26 X leuy. Shot 5 shot groups every half hour starting at 0600 until 1000. Groups gradually grew in size and moved up the paper about 3". This was shooting at 100 yds with ziltch wind.

    That range is now developed out to 1K meters with berms @ 200/300/400/500 meters a gong @ 1000 meters and a lava rock backstop out towards 1200.

    I'll be interested in your results.
     
  7. 41mag

    41mag Well-Known Member

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    Well this morning was fun for sure. The wife and I got to my bud's place sometime around 4'ish yesterday evening. I had totally forgotten about their neighbor up the road haveing a big birthday bash. But it only slowed us down a tad. We set up a clean target and got the .270 AM settled in at 300 yds. Due to the heat and mirage, we decided on a day break drop test.

    I hit the floor this morning @ 4 to find a thick fog had settled in the low land. Not good for seeing much less hitting anything. We headed down to the barn at about 6 since there was no way to get anything done any earlier. After setting up the shooting table, and placing a call to the daughter for local weather, we dialed in the current conditions into the pocket PC Exball program and waited for the fog to clear some. After what seemed an eternity, I just could make out the orange spot on top fo the 8' board we had put up at 500yds. Shortly after, we were off to the races. The rifle had been cleaned so the first rounds were foulers, and hit just a little low. After confirming the group we moved the board on out to 700 yds where I put two shots within 2.5" of each other. Then on out to 1000 yds. I must tell you that after only shooting at a 24" wide blind flange out there once, the 8" orange paster looked pretty damn small to say the least. But, I held fast and squeezed one off. First shot looked like dirt, second shot nothing, so we headed down to see what the deal was. The 700 yd shots were a little off ot the right so after not seeing any holes in the board, I put in 2 clicks left. Well by the time we got back to the barn a light breeze and started to move. First shot nothing same results on second. Then back to the board. Now before you all think I can't hit the side of a barn, the "board" is only a 1x10 we salvaged from the trash at work.

    So after looking at a few things and scratching our heads I figured, time to add another board. So we c-clamped another 8' board to the bottom of the first. Now we're in business. First shot a hit, second off the board. Then after turning in 3 click of right for the slight breeze, I put two more on the bottom of the board.

    So, I guess that I did a decent job of getting my drops in. We got accurate measurements at all ranges tried, and now have a load which will put those big 169'5gr Wildcats, into a nice neat group. I did fair considering I didn't have my glasses on for any of the shooting. I will hopefully get to head back up in a couple of weeks and we will actually dial things in and then should get in somewhat of a better group than just several hits on a board. The mirage got so bad, so quick, we were pushing things just to get in the shots we did. After things were said and done, I zeroed the rifle in for 500yds and will let it ride from there.

    All I can say is the hogs in that area had better get body armor because they are in for a whole new world of hurt. Also just for kicks, we had a small plate set up at 200yds, last week Tim shot it with the RUM just to see what it would do. The plate is some for of hardened stuff used for compresser valves. His shot is the rusty one, it was a 200gr Nosler AB at around 3200 fps. I put the first on in with the .270 and the 169.5gr right next to it. The crater is awesom, then we moved it out to 500 and I put one up at the top. It's about 3/8" deep as well. Can't wait to try the 195's.
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  8. Guest

    Guest Guest

    [ QUOTE ]

    All I can say is the hogs in that area had better get body armor because they are in for a whole new world of hurt.


    [/ QUOTE ]

    A 270 AM is some wicked medicine on hogs. Can't wait to see the pics and stories.
     
  9. 41mag

    41mag Well-Known Member

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    Hey Roy,

    I have shot up at our place many nights. I am not sure whats the deal is where your at either. Maybe the ground just holds the heat more than the sandy grassy area we shoot on. I generally use a couple of Colman lanturns with aluminum foil on half of the globe. Either type have worked using the liquid fuel or the LP type. Just set them up on a cinder block, a few yards up front, and off to the side a couple of feet and go for it.

    I generally only shoot out to 300 yards though, so to sort of be able to keep up with any roaming livestock. We generally check the area before shooting with a spotlight to be sure nothing has slipped in on us. Depending on where we at, we can isolate them on one place but not the other.