Originally Posted by Billinsd
Thanks for the post. Would you mind explaining bullet path?Thanks, I did not know that.So, do you mean lap the rings so I can get the gun to shoot to 1K, or to relieve the pressure points so the gun will shoot more consistently?
Also, would you mind posting the same data for 168 grain 7mm mag Bergers?
Drop: this is the amount the bullet drops at a given distance. the bullet leaves the gun level with the horizon, and will start to drop right away. We are not concerned with a zero, just the actual amount the bullet drops.
Bullet path: This is the path the bullet takes when zeroed at XXX yards.
Lets assume your 168 (3000 fps) is zeroed at 300 yards, and your scope height is 1.9 inches above the bore. The bullet leaves the bbl at an upward angle, crosses your line of sight on an upward path at about 25 yards. and is on its way back down when it crosses your line of sight again at 300 yards. at around 190 yards the bullet is actualy 4 inches high. Now, although your bullet is dead on at 300, the actual drop of the bullet is actualy 19 1/4 inches.
Now with the same setup, but at 1000 yards, without dialing up....just leaving the gun zeroed at 300 yards. Again, you bullet crosses your sight line on the way up at around 25 yards. It again crosses it on the way back down at EXACTLY 300 yards (300 yard zero) and the bullet will hit 214.54 inches low at 1000 yards. BUT.......you bullet actualy dropped 283 inches, its just that you had the gun pointed at an upward angle to your line of sight.
bullet path....-214.54 inches = 21 1/2 min of adjustment to hit dead on at 1 K.
Rings don't always line up exactly with each other, which binds on the scope tube when you tighten up the rings. Lapping rings is very important when you are using tapered rings-basses. Basicly, the lapping kit includes a steel rod, either 1 " or 30 MM, and some lapping compound. You install your basses and rings on the gun, take the top half of the rings off, put a little compound on the bottom rings, and slide the rod back and fourth untill the rod makes good contact with the rings. You are basicly sanding down the inside of the rings smooth and strait to prevent binding on the scope.
Also, I have seen factory guns where the holes for the scope bases are not exactly on center, or the bbl has a slight bend(we are talking thousands of an inch here, not a big amount). You can find the center of the adjustment on the scope, mount it on the gun, and be 4 feet off at 100 yards!!
Hope this helps. I did it in a hurry and deer gun season starts at noon, so i probably made some typos, spelling errors, among other things.
You guys feel free to correct me and I will check things over later.