scope mounting issues

[Mojave3]

Hey everyone,

Long post ahead...

First time deer hunter trying to get ready for a Sierra Nevada mule deer hunt. (More questions on that later...) Trying to do this as "on my own" as possible but help is needed.

I'm trying to mount a scope and have been running into problems. I did my best to follow Randy's scope installation video. It was great help but I'm still a rookie and need more advice.

The rifle is a Winchester Model 70 sporter in 270 Win. The scope is a Leupold VX3i 3.5-10x40mm. I used Leupold two-piece dual dovetail bases and rings.

First mistake: when installing the bases, I stripped one of the rear base holes. (Yeah, I was using a torque wrench, set slightly below the recommended in/lbs but it still happened.) A gunsmith was able to use a longer screw that engaged the threads deeper in the hole. He told me this should be fine and that I still had 3 solid points of contact with the other screws and this 4th one was good, but mentioned that switching bases in the future could be a cause for concern.

Next mistake: when seating the scope, I switched the position of the windage and elevation turrets. When the scope wouldn't zero I realized my error. It was embarrassing but easy enough to fix: back out the ring screws and rotate the scope to reorient it correctly and retighten the rings.

Now...it still won't zero. I'm still far right of the bullseye and I'm out of windage adjustment in the turret.

A little research tells me this is probably due to the receiver taps being out of alignment with the bore. It seems like the solution is to swap out the DD bases for Leupold standard windage-adjustable bases and remount the scope. But, being a newbie, I don't totally trust myself with the diagnosis.

So should I remount with windage-adjustable bases? Could it be something else? Is that partially stripped hole a problem?

Thanks in advance!

-Scott

 

[noharleyyet]

I had a similar issue with duals as the rear dovetail base was visually off center. It would still zero but drove me crazy because I was nearly out of windage. Adjustable rear base/ring would've solved but went talley steel instead.

I've done the windage/elevation switcheroo before. Stitched the hell out of a target before the lightbulb flashed. I've mis-mathed the clicks at short yardage sight-ins..etc. Mistakes are tuition.

I've also used too long base screws on a rem 760 and the slide wouldn't work.

 

[Melman]

before I bought my Wheeler scope mounting kit with lapping tool I used to just buy the DNZ game reaper mounts. they are awesome and are really good for the novice scope mounter. they are also very solid. some people don't love the way they look but they work very well. if you buy new rings you could go that route. will the scope move to the right, I know it wont move more to the left but will it move right? I once had a scope that broke internally and it wouldn't move the windage right or left at all. just stayed in the same spot no matter what I did with the turret. make sure it is in fact moving when you turn the turret

 

[Ben Lamb]

It's the rear dovetail. You can adjust your windage better by getting a rough zero using the set screws than the turret. I had the same issue with my 30-06 over the weekend and adjusted the base to solve the problem. Easy thing to over look, super easy to fix!

 

[noharleyyet]

It's the rear dovetail. You can adjust your windage better by getting a rough zero using the set screws than the turret. I had the same issue with my 30-06 over the weekend and adjusted the base to solve the problem. Easy thing to over look, super easy to fix!

I was assuming he had dual "fixed" bases.

 

[LCH]

Not trying to be a smart guy, but are you absolutely sure you're clicking it in the right direction? I've made that mistake before with a bow, adjusting sights in the wrong direction.

 

[Ben Lamb]

I was assuming he had dual "fixed" bases.

Aha.

I did not get that. Yes, switch the rear out for windage adjustable bases. Easy solution.

 

[Laelkhunter]

If you do decide to get the bases with the windage adjustment, don't forget to "center" the windage crosshair before mounting, and use the base adjustment screws for the coarse adjustment. Then you can finetune with the scope's windage turret.
To find the center, count how many clicks the windage moves total left to right, then divide by two. Adjust the scope turret back that number of clicks, and you should be close to center. That will leave you plenty of adjustment for sighting in.

 

[mtmuley]

Easy way to find center of windage and elevation. Hold a mirror over the end of the scope. Look through the eyepiece and you will see two sets of crosshairs. Line them up and the adjustments should be centered. mtmuley

 

[noharleyyet]

...learn something new every day, thanks mtmuley

 

[Ben Lamb]

Easy way to find center of windage and elevation. Hold a mirror over the end of the scope. Look through the eyepiece and you will see two sets of crosshairs. Line them up and the adjustments should be centered. mtmuley

cool tip.

 

[Laelkhunter]

Easy way to find center of windage and elevation. Hold a mirror over the end of the scope. Look through the eyepiece and you will see two sets of crosshairs. Line them up and the adjustments should be centered. mtmuley

Great info !! Thanks

 

[1_pointer]

Another option I'd suggest you consider is getting some Burris Signature rings with the inserts. You can use the inserts to give your self some more windage lee way. Reason I suggest this, is that I'd be more inclined to leaving the rear base on there since one of the screws holes is buggered.

 

[mtmuley]

If it was my rifle I'd have a smith drill and tap to 8x40. Then I would get the standard Leupold mount with windage screws if you still need adjustment after you center the reticle. mtmuley

 

[Mojave3]

Hey everyone,

I really appreciate all the advice.

Yes, the original dual dovetail based were "fixed" bases.

I just used mtmuley's awesome mirror trick to center the reticle and then confirm the windage and elevation turrets are adjusting the reticle position when moved. Seems a-ok.

I'll check out the Burris Signature rings as an option, though I think I'm leaning towards the Leupold standard windage bases. (I'm gonna talk to a smith about the time needed to retap to 8x40, too.)

Question on windage bases, is there a correct way to orient the rear base screws? I see pictures with then installed facing forward, towards the loading/ejection port, and with them at the back, facing towards the safety. Is it just a matter of being able to position the scope for proper eye relief or are there other considerations?

Thanks again!

 

[mtmuley]

All of my standard Leupold bases have the adjustment screws facing rearward. I'm sure the Burris rings are ok, but I personally don't care for any kind of insert in a scope ring. The main reason I suggested the re-tap is that stripped mounting hole would always be in my head. Glad you.liked th mirror trick. mtmuley

 

[noharleyyet]

Sometimes the scope tube's mounting dimension will predicate direction of rear ring base. I pull my scopes back quite a bit therefore I loose cradle the tube before torquing to decide. I believe all mine have the rear ring close to the ejection port & provide ample adjustment space. Have used the inserts with the optilock system for Sako & they worked great, but truthfully, and like mtmuley's statement, they got in my head some.

?? question; does 8x40 re-tapping require larger screw holes for bases?

 

[Mojave3]

Hey everybody-- thanks again for all the advice.

I went ahead and remounted with Leupold standard bases (windage adjustable). I ended up orienting the rear base with the screws facing rear-ward, as the scope seemed to fit best and give me the right eye relief.

That seemed to do the trick. After bore sighting and dialing in the windage with the base, I was zeroed pretty well and only needed to dial in the elevation on the scope.

The reticle is ever-so-slightly canted-- another rookie error-- but the set up is working. I'm getting nice groups out to 200 and 300 yards. The rifle definitely has its ammunition preferences (loves Federal, doesn't mind Remington and really doesn't like the "premium" Winchester lines) but that's a subject for another post.

I'll probably have that bum receiver hold re-tapped and remount when the season is over. I don't think I'll push my luck anymore with the CA X12 season opener only a few weeks away. It's been a learning experience and I'm glad for it.