longrangehunter
Handloader
- Jun 19, 2011
- 1,479
- 7
Ok, I'm not sure if this is new or old news, but it works very well for me and making sure I can hit exactly where I'm aiming if I've done everything else right, so here goes.
The scope should be mounted so the cross hairs are inline with the bore axis. Here's how to set it up so that as you dial into the elevation the bullet tracks correctly.
Have a known accurate load for the gun to do this test, and/or as accurate as the gun will hold at 100 yards/meters.
After mounting your scope and it is sited in, attach a large piece of cardboard at least 4' in length and mark a plumb line on it as long as you can in the middle. Place a mark, X or whatever 6" from the bottom on the plumb line drawn. Depending on whether your scope is in Mils, or MOA and the graduation of the scope come up 18" from that mark at the bottom and place another X on the plumb line, and one more 18" further up on the plumb line, the last one should be at 36" from your bottom mark. If you have a lot of turret adjustment range then you could go up another 18" but it is not necessary.
Note: This may need to be varied" IF" your scope does not have enough elevation range in your turret scope adjustment? If you don't have 36" of adjustment at 100 yards this will still work the same for setting up the scope, only your bullet will hit the cardboard further down from the upper most mark used.
Ok, here's what you want to do. Aim at the bottom X placed on the plumb line and fire one shot. It should be very close to the plumb line mark, either dead on, right or left but it wont really matter.
Aim and fire a 2nd shot at the bottom X only this time dial in 5 mils or 17.25 MOA into your elevation adjustment on the scope. The bullet hole should land on the same side and distance away from the plumb line as your first shot, or be dead center of the plumb line, either case it should be the same! And that is the important part!
Dial in another 5 Mils or 34.25 MOA and fire a 3rd shot while still aiming at the bottom mark you placed on the cardboard. Your bullets hole(s) should still be tracking the plumb line you marked and the same distance from that line drawn!
Ok, if you mounted your scope correctly and your round is accurate enough the bullet holes should be moving up the cardboard in a vertical line that is plumb (straight up and down). If the round fired at the bottom X mark is on the RIGHT side of the plumb line and the 2nd round is dead center and the 3rd is LEFT of the plumb line your scope will need to be turned Clockwise in your rings! Or Counterclockwise if the rounds fired are tracking Left to Right.
What your looking for is that as the adjustment(s) are dialed into your scope, that it tracks correctly up and down the plumb line drawn. If it doesn't, the amount needed is a very small turn clockwise or counterclockwise, and I mean very small unless you're way off.
Not only will this tell you if your scope is mounted properly inline with the bore, your scope should also be tracking correctly for the amount(s) of adjustments made. ie: 5 mils should change your POI 18" and so on.
This only needs to be done one time once successful. It is a trial and error method but this is the best way to make sure your scopes cross hairs are inline with the bore. Apply some masking tape with a line drawn on it to the rings and the scope so you can see the movement within the rings while turning.
This really only matters for extreme precision shooting as the distances become greater and greater. But you'll be happy you went through all this trouble in the beginning so as you begin your long range shooting your bullets are where they should be based on your dope.
Good luck.
The scope should be mounted so the cross hairs are inline with the bore axis. Here's how to set it up so that as you dial into the elevation the bullet tracks correctly.
Have a known accurate load for the gun to do this test, and/or as accurate as the gun will hold at 100 yards/meters.
After mounting your scope and it is sited in, attach a large piece of cardboard at least 4' in length and mark a plumb line on it as long as you can in the middle. Place a mark, X or whatever 6" from the bottom on the plumb line drawn. Depending on whether your scope is in Mils, or MOA and the graduation of the scope come up 18" from that mark at the bottom and place another X on the plumb line, and one more 18" further up on the plumb line, the last one should be at 36" from your bottom mark. If you have a lot of turret adjustment range then you could go up another 18" but it is not necessary.
Note: This may need to be varied" IF" your scope does not have enough elevation range in your turret scope adjustment? If you don't have 36" of adjustment at 100 yards this will still work the same for setting up the scope, only your bullet will hit the cardboard further down from the upper most mark used.
Ok, here's what you want to do. Aim at the bottom X placed on the plumb line and fire one shot. It should be very close to the plumb line mark, either dead on, right or left but it wont really matter.
Aim and fire a 2nd shot at the bottom X only this time dial in 5 mils or 17.25 MOA into your elevation adjustment on the scope. The bullet hole should land on the same side and distance away from the plumb line as your first shot, or be dead center of the plumb line, either case it should be the same! And that is the important part!
Dial in another 5 Mils or 34.25 MOA and fire a 3rd shot while still aiming at the bottom mark you placed on the cardboard. Your bullets hole(s) should still be tracking the plumb line you marked and the same distance from that line drawn!
Ok, if you mounted your scope correctly and your round is accurate enough the bullet holes should be moving up the cardboard in a vertical line that is plumb (straight up and down). If the round fired at the bottom X mark is on the RIGHT side of the plumb line and the 2nd round is dead center and the 3rd is LEFT of the plumb line your scope will need to be turned Clockwise in your rings! Or Counterclockwise if the rounds fired are tracking Left to Right.
What your looking for is that as the adjustment(s) are dialed into your scope, that it tracks correctly up and down the plumb line drawn. If it doesn't, the amount needed is a very small turn clockwise or counterclockwise, and I mean very small unless you're way off.
Not only will this tell you if your scope is mounted properly inline with the bore, your scope should also be tracking correctly for the amount(s) of adjustments made. ie: 5 mils should change your POI 18" and so on.
This only needs to be done one time once successful. It is a trial and error method but this is the best way to make sure your scopes cross hairs are inline with the bore. Apply some masking tape with a line drawn on it to the rings and the scope so you can see the movement within the rings while turning.
This really only matters for extreme precision shooting as the distances become greater and greater. But you'll be happy you went through all this trouble in the beginning so as you begin your long range shooting your bullets are where they should be based on your dope.
Good luck.
