Re: Need help anyone / zero-ing
Agree with all answers.
Did you go back to 25 to re-check your zero to make sure something is not fubar (like a broken or loose scope etc)?
With a standard .223 and a scope height of 2.25" (pretty high) at about 55 grain a 25 yard zero the bullet trajectory will put you about 5" high at 100 yards +/- depending on the actual bullet, actual scope height and whether or not you are really zeroed. If the distance from the aim point to the edge of your 100 yard paper is not more than 5" +/-, you are guaranteed to be off the paper. If you have way more than 5" of paper above your aim point at 100 yards (like tackleberry suggested) and you are still not "on paper", then you have something else going on. So, your first option is to do what tackleberry suggested - find a giant piece of cardboard and march right back out to 100 yards with an aim point that is in the middle of the cardboard and see what happens (after you re-check your 25 yard zero to make sure something is not fubar).
Your other option is what 58blackflag and rick 324 said - zero at 50 yards before going to 100. Your 50 yard trajectory will be only 2" high at 50 with your 25 yard zero. Once you then re-zero at 50 your new 100 yard trajectory will only put you a little over 1" high at 100 yards. Alternatively you can zero a little less than 0.5" low at 50 and you will be very close at 100. You then go to 100 and re-zero there.
For next time you need to zero, you should be able to look down the bore at 50 yards even with a 223 (after swiveling the action out of the way for an AR - like you were going to clean it), line the bore up with a big bright target aim point, adjust your elevation and windage until the bore and the scope cross hairs both point at the same thing (looking back down your bore and re-zeroing bore picture on aim point every time you adjust el/win), and then your first shot at 50 should be within a couple of inches +/-. With one or two more shots you should be able to zero at 50 so you will be about 1" high at 100 so that one or two more shots at 100 with adjustments in between will zero the scope.
For not too much money you can also get an inexpensive bore sight laser - if you are willing to spend a few bucks check that option out for next time too because you can go straight to 100 yards and with two or three shots be ready to shoot test groups to settle in the scope.
There are several free ballistics calculators on the web - just google "online ballistics calculator" and try a few until you find one you like and that allows for any zero setting and plots the bullet trajectory. Put in your bullet data (should be a pull-down menu for cartridge type and bullet weight if the calculator is one of the good ones), your scope height (there are posts on the hide for how to measure this) and your zero range. Then run the data to look at your trajectory - this will allow you to see exactly what is going on when you zero at 25, 50 etc so that next time you will know what is happening and be able to get it all down in 2 or 3 shots. You can also try varying the scope height in the ballistics program to learn what happens to the 100 yard poi with a 25 yard zero. You can also plot out beyond 100 yards to see where the bullet crosses zero again on the way back down - this will give you the entire picture of what scope height does to your accuracy when you just "shoot the cross hairs" without hold over or hold under - the higher the scope height the more "rainbow" you get in the bullet trajectory for a given zero distance.
Good luck!
