Home Forums Hunting & Shooting Hunting Optics Scoper mounting woes

I bought a used model 70 that came with Weaver(or Weaver style)bases. I bought some new Weaver rings to mount a Tasco Pronghorn scope. I got the scope with another rifle, and had never used it. After using up all the adjustment in the scope, the POI was still about a foot high, and a foot right at 100yds.

I replaced the Tasco with a Nikon Buckmaster that I had been using on another rifle with out any prolbems. Using up all of the adjustment in the Nikon placed windage correctly and the elevation was still about 9" high at 100yds.

I replaced the Weaver rings and bases with Leupold dual dovetail bases and rings. With these rings and bases the Nikon was easily adjusted to the correct elevation, but using all of the adjustment the windage was still 3 1/4" out at 25 yards.

What is the next step in trying to get a scope mounted on this rifle? Is some thing I'm over looking in mounting these scopes?

Since you tried two different mounts it seems that the holes in your receiver are out of line? Lay a straight edge over the holes and see if it's in line with the barrel.

You could try to reverse the Weaver bases but I would bet that they are quite uniform. It would not cost much to try however.

Mounts that have windage in them are the traditional Redfield style with the opposing rear screws that Leupold and others still make. Others are the Burris Signatures with the insert kit and the cheapest are the Millets which work for me but others report broken parts.

Keep in mind that when we use up say all of the windage that takes away from the elevation and vica versa.

Other options are to shim the bases but then the rings might be even more out of line. Also can the rifle be returned and how does it group?

It sure helps to have a good bore sighter at times like this or even a place to rest the rifle and bore sight it out of the window at home.

Since you already have the windage adjustable double dovetails you are most of the way there. First get your scopes windage adjustment centered, counting the total turns from end in the other and going back half will take care of that. (Close enough anyway) Then use the rear windage screws to bore sight it, then sight in normally. Since you have no problem with elevation this should solve your problem.

Dual dovetails with rear windage screws?

I'll have to look more closely at the Burris ones to see if they would give me enough correction. I'll see what I can do about checking the alignment of the holes. I had hoped to avoid the Redfield style, but may have to resort to it.

It isn't obvious to me how the windage can be adjusted on the dual dovetail mounts.

You might want to try the Burris Signature rings that come with inserts. For a nominal fee, you can buy a set of offset inserts that will allow about 20" of adjustment at 100 yd. Both windage and elevation can be adjusted with this set up.

While I've come to use the Dual Dovetail lately your situation seems to call for the windage adjustable type mounts or get a Gunsmith to go a size up on the base mounting screws and recenter the holes. You may be so far out of whack that even that wouldn't work well. Easy way would be using the windage adjustable bases IMO.

Youper,
Oops, I'm on the wrong base! <img src="/ubbthreads/images/graemlins/blush.gif" alt="" /> As soon as I saw "Dovetail" I automatically assumed the rotary dovetails of Redfield pattern. Never assume anything I guess. <img src="/ubbthreads/images/graemlins/blush.gif" alt="" /> Switching to that type or something else windage adjustable would solve your problem though, which would appear to be misaligned mounting holes.
model70guy

I had a partial success this afternoon. I took off the mounts and put the screws in. With a good straight edge I couldn't detect any being out of the line they formed. I set up the rifle like I would to bore sight it, and tried to "aim" with the mount screws. I couldn't see anything wrong. I tried all four permutations of reversing the bases and boresighting with the scope centered up. All results were the same a when firing.

In a last ditch effort to see what was going on, I took a VX-II off another rifle and centered it up. Bore sighting that one showed the scope only off by half of what the Nikon was. I packed up and headed to the range after adjusting the windage to the bore. With a few shots I got it sighted in at 100, but I used nearly all of the windage adjustment. I also had to adjust to about halfway to the bottom of the elevation, but this is at 100.

I had wanted to use this scope on the rifle it was on, but in view of the trouble I think I'll leave it. The rifle is a .30-'06. With Korean Ball ammo from the 70's and Winchester 150 powerpoints, on 3X, it grouped two inch three shot groups, but I think it can do better. I think it might be time to look closer at the Burris ones though. Thanks guys.

Also, while you are troubleshooting, check for a bent barrel.

Good luck.

+1 for Burris Signature rings and Pos-align inserts. You can also use 2 sets of inserts to get up to 40" of correction @ 100 yds. Plus they also take care of situations where the two halves of a two-piece base are not aligned to each other either.

Andy