Zeroing

c_hatch

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A friend of mine has been having trouble with his rifle. He has gone to sight it in and everything is fine at 50yrds. We shot a match last week and even out to 100 he was hitting targets. When shooting out to around 200 he is WAY off, 2 foot high and 1 foot left. I let him use my rifle and everything was fine for him after that. We initially thought that he was just jerking that bad at longer distances but using my rifle he was hitting longer range targets. Any idea of the cause of his rifle being that far off at 200+ yds? My initial thought is that wrong scope mount?
 
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Was he holding over at 200? He should be relatively close to dead on at 200 with a 50yd zero
 
Jesse Tischauser said:
50 yard zero is elephant dung. You could be way off at 200. Always zero at 200 or 300. Then shoot at 50, 75, 100, 150, 400 etc to know your ballistics.
Sho nuff
 
Never was a fan of the 25 or 50 yard zeroes either. I use a 100 yards zero in my 3gun AR, but that's because my optic is designed for that and has hold overs built in. Normally I would use a 200 or 300 yard zero.
 
With a 100 yard zero, all corrections will be positive, meaning the bullet will be below the line of sight for all ranges except 100. My Burris MTAC 1-4 has holdover dots that are spot on out to 600 using the American Eagle 55 gr M193 round. The elevation issue with your friend is easy, but to hit a foot left at 200, if it's a consistent group, probably means the scope isn't level. Have him fire a group at 100, then make only elevation correction and fire another. If the group wanders to the side also, remount the scope.
 
David Marlow said:
With a 100 yard zero, all corrections will be positive, meaning the bullet will be below the line of sight for all ranges except 100.
That's the main reason that I use (and recommend!) the 100-yd. zero. Well, that and the 100-yd. indoor range, twenty minutes from my house.
 
With a 100 yard zero, all corrections will be positive, meaning the bullet will be below the line of sight for all ranges except 100. My Burris MTAC 1-4 has holdover dots that are spot on out to 600 using the American Eagle 55 gr M193 round. The elevation issue with your friend is easy, but to hit a foot left at 200, if it's a consistent group, probably means the scope isn't level. Have him fire a group at 100, then make only elevation correction and fire another. If the group wanders to the side also, remount the scope.
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Ding ding ding! Winner! Easy way to check is draw a vertical line on a piece of cardboard, make sure it's plumb, stick a small target near bottom, and use each bullet drop mark on target. Obviously, the groups should track up the drawn line. Same exercise will also confirm if you are getting the ballistics you expect if you cannot shoot longer ranges.
 
Buy Strelok Pro or some other quality ballistic calculator. Use that to find a load that meets your zero / reticle needs then as Jesse said, shoot at all those distances to confirm the zero. You can use the data for your selected load to extrapolate your zero at 50, 100 and 200 etc, but you do still need to shoot to confirm.
 
Zero at 200, buy Strelok Pro, learn to use it.
Confirm 20, 50, 100, then 300 and 400.
Or, just buy a Vortex Razor w a JM reticle, zero at 200 and just play.
Inside of 50 it will be one or two inches low. 50 to 150, one or two inches high. 200 dead on. Use the hash marks for 300 and 400 (of course confirm)
It isn't rocket science.
But, most important thing is, as Jesse says; just doing a 50 yard zero and going to matches expecting hits at 200 and beyond is just ignert.
It can work, but it would more than likely not. And the further away ya get, the worse it will be.
 
Strelok Pro is a great app. I used it to get a general idea of were mt rifle would hit at range and it was pretty much dead on. One thing I did that helped is you can build you load within the app if you have a chrono and know your fps. Even before building the load in the app, it was still close wnough for me to get hits at range.
 
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