sight in help

Discussion in 'Long Range Hunting & Shooting' started by lamiglas, Jul 13, 2008.

  1. lamiglas

    lamiglas Well-Known Member

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    My father in law has a winchester model 70 .264 winchester mag. I called winchester and the serial number indicates that it was made in 1964. the problem: we mounted a vari-x III 3.5-10 x 50 with target turrets on it using dual dovetail leupold rings and bases. there is not enought adjustment in the scope to zero it at 100 yds. at the range, it was 12 inches low at100 yds. I called leupold and they sent me two shims. after installing the shims I put a laser borsighter in the barrel and now i can bring the laser and crosshair almost together. the laser (barrel) is still 1/2" lower than the crosshairs (at 20 yds) with the scope adjusted all the way up. I havent test fired it yet but if they are just coming together at 20 yds, how high will it be at 100 yds? will there be any adjustment left for dialing in at further distances? it will be 2 weeks before i can shoot it. (father in law bringing ammo at that time). leupold said each shim would give me 12 inches at 100yds so based on this i expected to be able to dial the scope where the laser was quite a bit above the barrel. any suggestions would be very much appreciated.
     
  2. Tyler Kemp

    Tyler Kemp SPONSOR

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    Aug 10, 2006
    Well you have a bit of offset between the barrel and scope. You should be several inches high if you are almost touching something from the barrel to the crosshairs at 20 yards.
     

  3. britz

    britz Well-Known Member

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    If you are at .5" low at 20, that means that your bore has already raised about 1 inch because scopes usually sit about 1.5" above bore line. I would guess that you would be sighted in between 150 and 300 yards then, but that is just a very rough guess. I ran it through JBM and had a zero for 200 yards and it said that at 20 you would be .6 low. If your scope is topped out, you wount be able to sight in for farther, but if your scope is bottomed out, you may be OK. However you shouldn't make it a practice of topping or bottoming out your scope on a regular basis because it can become hard on your scopes adjustment mechanisms. Either way I would use Burris sig rings with the tapered incerts to correct the problem.
     
  4. silvertip-co

    silvertip-co Well-Known Member

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    Check it at a closer distance. Center both your knobs. At 6-10' from muzzle the scope should be 1.5" above bore. If higher than 1.5" you need lower rings, if less than 1.5" you may be ok as the closer to the barrel you are the more up you have. On M40 sniper rifles the USMC machines a hair off the front of the solid Redfield base to get the scope a hair closer to the bore, that gives them more 'up' as they zero the.308 at 500yrd and shoot to 1000yrds(over the head under the b_lls).

    Throw your boresghter away pull the bolt and look down barrel to boresight it the right way on your targeted garage wall, after you have the rifle level and plumb and all knobs centered. Remember at 6-10' to sight 'up' to the center + you use the down elev knob, to go down to the center you go up on the elev knob. At 6-10' from muzzle the scope knob direction is reversed(physics of light/lenses).

    Doing it on the kitchen table works as well if wife dont mind the + you made on the wall with a permanent marker. The Redfield ( Leupold if you wish) ring mount system is a very good one and should cause no probs if you have the correct one of the 4 ring heights (super low, low, medium, high)Redfield made. The one piece Redfield base is waymo better than the two piece bases, but both or good. If the Redfield system wasnt good... thousands of M40 sniper rifles wouldnt have it. Less pieces less trouble.

    Heck even Weaver makes a one piece base for bolt action rifles, and some even have the machine cutaway so the action opening isnt covered. But thats deeper in the Weaver catalog than most guys look. Heck the Picatinny rail is just Weaver base with more scope screw slots milled in it (wish I'd a thot of that instead of Unka Sam).

    Oh yes and one more thing, endeavor to always stay away from shims. They are just .010" of trouble for a shooter.
     
    Last edited: Jul 14, 2008
  5. long450

    long450 Well-Known Member

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    I would buy a different set of mounts and confirm that the mounts are correct. If that did not sove the issue, I would put the scope in the rings of a different rifle and see where it shoots. There is somthing wrong here! You should not even be closed to having the scope adjustment all the way up. Are the rings or bases capable of being reversed? Do you have the front base in the back and vice versa?