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sighting in

Gene248Gene248 Member Posts: 356 ✭✭✭
edited December 2013 in Perry Shooter Competition Shooting and Reloading Forum
I do not have a place to shoot at long distances so I went to an indoor range to sight in my 243 and 25/06. They are both dead on at 25 yards. What type of adjustment do I need to make on the scope to get my rifles to shoot 3" high at 100 yds? I used to have it written down but can't seem to find it now.
Thanks
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Comments

  • festusfestus Member Posts: 1,008 ✭✭✭
    edited November -1
    I used to use remshoot or something like that. Found it on Remington.com a few years ago. Don't know if it is still available or not, but just select bullet weight and yardage and it shows where it will hit at different yardage.
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  • charliemeyer007charliemeyer007 Member Posts: 7,250 ✭✭✭
    edited November -1
    Hornady has a nice free ballistics program.

    http://www.hornady.com/ballistics-resource/ballistics-calculator
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  • bpostbpost Member Posts: 32,643 ✭✭✭✭
    edited November -1
    Gene248, unless you have a magic ball you will never know where that bullet will strike at 100 yards. Some time ago I tried several times to use 25 yard targets to adjust for 100 yards with different rifles, it was a failure. Although the 100 yard hits were on the paper they were seldom in the black usually many clicks in elevation off of center. Some were off by inches in windage too.

    There are too many variables in rifles, scopes and ballistics to extrapolate much useful data when shooting very short ranges and trying to figure hits at long distances.

    You owe it to yourself and your intended game to shoot at distances you expect to hunt at. Find a range, even if you have to drive a long way to do it. You will be more confident and accurate too.

    My .02
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  • Gene248Gene248 Member Posts: 356 ✭✭✭
    edited November -1
    ok, thanks guys. I do know that different loads and rifles will shoot differently at the same range. Guess I really will have to make a drive to an outdoor range to get these rifles shooting exactly the way I want them to shoot. I may get to hunt one day before my neck surgery which will put me out of hunting and shooting for a while. I want the guns right before I get the chance to go.
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  • charliemeyer007charliemeyer007 Member Posts: 7,250 ✭✭✭
    edited November -1
    I would play with the program to get an idea. You can change the numbers for the zero to see what yields point of aim at 25 yards. Guessing the velocity and bullet drag function is done by looking in a loading book. Nothing beats actual field checking at the actual distance.
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  • perry shooterperry shooter Member Posts: 17,390 ✭
    edited November -1
    The big thing to consider I how high the center of the scope is above the center of the BORE. a rifle that is dead on at 25 yards . with low bases mounting the scope will be at one place at 100 yards . While the same rifle will be different with High rings sighted dead on at 25
    yards will shoot higher at 100 yards
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  • CheechakoCheechako Member Posts: 563 ✭✭✭✭
    edited November -1
    The age-old method of sighting dead on at 25 yards with a scope and 12.5 yards with iron sights was never meant to replace actually shooting at yardage. It was a simple way to ensure that your first shots at 100 yards would be on paper, although high. I've used it many times over the years and it has always worked for me. It can be a life-saver in the field when you have a wreck and damage your sights and sight settings.

    The same is true of ballistic charts. They will get you on paper as far away as 1000 yards but cannot replace a few real-world shots.
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  • navc130navc130 Member Posts: 1,160 ✭✭✭
    edited November -1
    My experience with 30-06 caliber bolt action rifles, standard height scope base: sighted one inch high at 25 yards was very close to dead-on at 100 yards.
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  • Gene248Gene248 Member Posts: 356 ✭✭✭
    edited November -1
    I am going to an outdoor range this week to check both rifles in actual conditions and yardage. I have two 243's, a 270, and a 25/06 that are all new to me guns. I have only fired at the indoor 25 yd. range to get them ready to take to the outdoor range. My original question was to be sure I should be on the paper at 100yds. When I shot all the time years ago I had written down for each rifle I owned how many clicks I needed to adjust the scope from 25 yds. to 100 yds. in case I happened to bump the scope I could sight it at 25 yds. and then adjust for 100 yds. and be real close. Not dead on but pretty close.. It worked pretty well as long as I was using the same loads in the same guns.
    I appreciate all of your responses. Thanks for the help.
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  • sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    quote:Originally posted by Gene248
    I am going to an outdoor range this week to check both rifles in actual conditions and yardage. I have two 243's, a 270, and a 25/06 that are all new to me guns. I have only fired at the indoor 25 yd. range to get them ready to take to the outdoor range. My original question was to be sure I should be on the paper at 100yds. When I shot all the time years ago I had written down for each rifle I owned how many clicks I needed to adjust the scope from 25 yds. to 100 yds. in case I happened to bump the scope I could sight it at 25 yds. and then adjust for 100 yds. and be real close. Not dead on but pretty close.. It worked pretty well as long as I was using the same loads in the same guns.
    I appreciate all of your responses. Thanks for the help.


    First thing you have to do is measure the actual distance from center of scope to center of bore. Plug that measurement in to a ballistic calculator and calculate using about 100 fps slower than published loads for actual loads. From what I can determine using a 1.5" Bore to scope center is right at about 0.0 @ 25 yds. for all three using most common loads off the shelf.

    Of course, just like a ballistic calculator, going off a 25yd/m zero needs to be verified at long range. Preferably before you shoot at an animal thinking you know the zero at that longer range. No need to get fancy verifying. A rock or stump at approximate distance will suffice.

    FWIW, I zero most of my rifles 4" above center @ 100 yds., to have a dead on zero at 300. A 3" high zero with most common loadings in the chamberings you give, will put you 4"-7" low @ 300. I'm fortunate in that I can verify for long when I shoot at 25.
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  • Gene248Gene248 Member Posts: 356 ✭✭✭
    edited November -1
    All riles sighted in and ready to go.
    Thanks for the help
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