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Posted: 2/2/2008 2:41:30 PM EDT
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Anyone have a good link that explains the proper way to zero or sight in a scope? I am a bit confused about point of aim, line of sight, and line of the bore. What I would like to do is set my scope up so that it is 'true with the bore' and be able to strictly adjust off the ballistics of the round. In short I am lost when it comes to 'hold over bore'/compensating for the distance the scope sits over the barrel. Thanks in advance for any help. |
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Start small. Your first rounds should be at about 25 yards. Take your time & shoot as tight a group (3 rounds minimum, 5 is better) as you can. Then measure how far (in inches) your group's center is from your point of aim. At 100 yards, 1 inch (to be perfectly accurate, it's 1.04... inches, but the difference is not important at this range) is eqivalent to 1 minute of angle; therefore, at 25 yards, 4 minutes of angle is equivalent to 1". Example: If the group you fired at 25 yards is 2" high (8 moa) and 1.25" (5 moa) right of the point of aim, you'll need to adjust your scope for this difference. If the scope is calibrated for 1/4moa adjustments (1/4" in 100yds), then that's 4 clicks per moa. So you'd need to adjust your scope down 32 clicks and left 20 clicks. Then shoot again at that distance to see how close your adjustments got you. Once you're hitting point of aim at 25 yards, you're ready to move out to longer distances. If you're shooting a .30-caliber rifle, you should now try shooting at 200 yards but without changing your scope settings. You should be within 1 moa (that'll be within 2" at a distance of 200 yards) or so of your point of aim. For a .223, you're going to be a little high (how high depends on barrel length and rate of twist) at 300 yards with your 25 yard setting. Adjust as needed. Then shoot at different distances & determine what adjustments you'll need to make to be on-target at those ranges. Write everything down! Then tape a 'cheat-sheet' to your rifle. |
| GrinReaper...thanks as that was a huge help for someone new to rifle shooting. With that said, I just won a Leupold Mark 4 1.5-5x20mm Mid Range / Tactical M2 Riflescopes and I don't have a clue in how to use/sight it and don't know anything about it's bullet drop compensator. Do you by any chance have any thoughts or ideas? I've got it mounted on an S&W MP15. Cheers!! :) |
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hooka, I'm glad that it helped , and congrats on the win! Sighting it in should be pretty much the same as for any scope, with a little difference here [the following assumes a .223/5.56 rifle, which hooka's is]: instead of sighting in at 25 yards, try sighting in at 50 yards, using the 200 yard point on your BDC as your 50 yard point (I'd make sure you are hitting the paper at 25 yards first, though, just to get your first 50 yard group usefully close to the target). Once you are satisfied with your 50 yard accuracy, try shooting it at 200 yards -- remember, you are using the same point on the BDC for both 50 yard shooting and for 200 yard shooting. Once you are zeroed at 50 yards, it will be very, very close to being on-target at 200 yards, so adjustments to get it 'just right' at 200 yards should be minimal. Remember, bullet drop compensators are usually set up with a specific bullet weight/velocity, barrel length, and height over bore of the scope in mind, so first READ the MANUAL (you would have thought of that yourself, but if I don't say it, someone else will). If your set-up is not the same as the scope's designer had in mind, your BDC will not be on-target at all ranges. Of course, you can always figure out (trial & error) what the difference will be a various ranges, and adjust your scope for them -- as above, write them down and keep this info with your rifle. edited to highlight my spelling skillz |
| Hey GrinReaper. Thanks again as that's a ton of help. I sighted it in over the weekend and that was actually more fun than shooting it! So hats off for taking the time to help some of us that are higher up on the "ignorance" scale...hopefully I can repay the debt to someone else in the future. Cheers!! |
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