I finally gave up on the idea of my right eye ever recovering to the point that I can shoot with it and ordered up a couple of left handed bolt rifles.

One is a Ruger 77 Mk. II originally in 7mm Remington Magnum, which I sent to Clearwater had rebored and rechambered to .358 Norma Magnum. I first got my hands on it yesterday, and of course I had to cobble up some loads and try it out today.

The rifle did not come equipped with rings, and the only Ruger rings I could find were already in use on a .270 Winchester Number 1, but I took them and the scope, a 4X Lyman All American Perma Center, off and installed them on the new Model 77.

However, when I went to bore sight it, the scope was way off for elevation. I finally cranked it up to the point that it bore sighted, but the first shot at 25 yards was low and right. I used up all the left windage getting the point of impact centered up, and using all the elevation still left the POI about 6" low at 50 yards.

I have seldom used Ruger integral bases and rings and this situation has me baffled. Any suggestions on how to deal with the problem would be most welcome. (The rifle did produce a five shot group into one hole at 50 yards, whoever.)

Oh, and in response to a recent post inquiring about barrel wall thickness for a rebore, the muzzle of this rifle measures .560", leaving almost exactly .100" wall thickness after the rebore. I think that is probably the minimum.

The number 1 uses two identical height rings. The 77 uses one ring that is higher than the other. Go to Ruger's web site and it will tell you what you need.

Well, that solves the riddle of the elevation. Now if I could only find a solution to the windage problem.

Many thanks, LJS. I should have thought of that, considering the difference in height of the bridge and the receiver ring on most bolt actions.

The other rifle, a Model 70 Winchester, which I had rebarreled in .308 Winchester, should not present such a problem. It is due in on Thursday.

You could always remove the locating stud on the rear ring and gradually increase the dovetail depth on the base until it prints in conjunction with the scope windage centred.

quote:

Originally posted by xausa:
Well, that solves the riddle of the elevation. Now if I could only find a solution to the windage problem.

Many thanks, LJS. I should have thought of that, considering the difference in height of the bridge and the receiver ring on most bolt actions.

The other rifle, a Model 70 Winchester, which I had rebarreled in .308 Winchester, should not present such a problem. It is due in on Thursday.

The windage problem will likely be resolved once you have get the correct height ring combination as per LJS's post. You need to 'centre' your scope adjustments both horizontal and vertical as the starting point for adjusting to the correct POI on target. Depending on the type of scope adjustments,but often if either of the adjustment ranges on a scope are too far off centre, the other range can be affected too e.g as you adjust a POI a lot vertically the POI can start and move correspondingly left and vice versa.

quote:

Originally posted by eagle27:
[The windage problem will likely be resolved once you have get the correct height ring combination as per LJS's post. You need to 'centre' your scope adjustments both horizontal and vertical as the starting point for adjusting to the correct POI on target. Depending on the type of scope adjustments,but often if either of the adjustment ranges on a scope are too far off centre, the other range can be affected too e.g as you adjust a POI a lot vertically the POI can start and move correspondingly left and vice versa.

Good point, and again something I should have realized,

Before you mount any scope, first of all turn the adjustments from a dead stop (end of the adjustments) then turn to the other end counting the full turns to that dead stop. Now turn the adjustments half way back..Now you are in the center of your adjustments and/or the focal plane of your scope...Now mount the scope to bore sight or even sight in without turning the adjustments very much, usually a couple of clicks and you sighted in, and you will have a lot of adjustment both up and down, handy for load changes, and still in the focal plane of the scope, The scope will now hold adjustment better as the tension is less, be clearer out to the edges and so it maintains zero better..Without mount/base adjustments your at a disadvantage unless your a gunsmith that can mill cut to zero, with adjustable mounts you can shim if you have to to stay close to center, but usually not a problem unless the receiver is out of square to the world as some are..However I have never had a problem with a Ruger or Brmno mod. 21 as to the focal plane of the scope..One a Mauser or mod 70 you can hand surface grind the receiver and hand fit the bases and thats a plus as you can sight in without changing for center or focal plane..All my rifles are fitted up this way, and never seem to change or lose their zero..short of wood warping I don't expect them to. I have not had to deal with wood warpage in a number of years..Glass bed factory guns and use good wood in custom guns is part of that reason I suppose.

I do think too many folks just stick a scope on a gun and go hunting, and a lot of them get away with it for a lifetime, in fact most do well with that approach..