What is the best way to mount a scope on a rifle?

[Ru4real]

What is the best way to ensure a rear Leupold mount is aligned properly to the rifle bore?

I know why it happened, and I plan to check out to 600 yards, but there must be a better way. One of you probably know a better way.

I recently completed work on four previously dialed in rifles. The work necessitated scope removal. For all four guns, I left the scopes in the bases and removed the scope and rings as a single piece. After the work, I reinstalled the scopes and rings on all four guns.

Today checking zero, one gun was still dead on at 100 yards, no adjustment needed. Two guns needed a couple clicks and then they were dead on at 100 yards.

The 4th gun didn’t touch the target at 100 yards. I moved the target to 25 yards, shot, and the bullet was way right, so I dialed in a bunch of windage so it was dead on windage at 25 yards. Moved target to 100 yards, shot, and I was still six inches right. So I dialed in more windage and hit the turret stop. Uh-oh.

I looked at my Leupold rear mount and noticed when I reinstalled the scope and bases as a single unit last weekend, I had mounted it to the extreme right. So I loosened my rear mount, centered the mount by eyeball, and then tightened the rear mount. I removed all of the scope windage I had dialed in. I shot and I was now back on paper at 100 yards. I then shot a good 100 yard group.

Other than to shoot at 200, 300, 400, 500, 600 yards I don’t know of a better way to confirm proper horizontal alignment. Previously this gun was spot on for windage at those distances.

Here is the mount in question. Leupold STD mount and bases.

View attachment 997128


I watched this video, but nothing he did or suggests will help my situation. He sort of “eyeballed” the mount as well, LOL.

 

[Ru4real]

Here is the mount on the gun in question. Winchester M70 CRF 7mm Rem Mag, Krieger barrel, Hogue stock, Burris scope.

View attachment 997134

 

[lightman]

With that style mount I center the scopes adjustments and eyeball the rear base to get it centered. If this "eyeball" method hits the target near the center I'll leave it alone and finish zeroing with the scope. Use your judgement about whether (near the center)is close enough for you. I prefer my scope adjustments to be close to centered when zeroed. Thats one of the good things about a Picatinny style rail.

The rear adjustment type of mount has gotten a lot of bad mouthing over the years but I have several rifles with that type of mount that have served me well. I reserve the Picatinny type mount for my Varmint rifles where weight isn't as much of a factor.

The older style Redfield rings with the bottom screws make a classic looking mount on a blue steel wood stocked rifle!

 

[mshootnit]

I have a big torque wrench with a smooth chrome 1" handle. I put that bad boy in there and make sure it runs back and forth easy. That at least lets you know that the rings are aligned to each other. If you did the front ring straight and cinched up the rear screws evenly it should be good to go.
I like a single picatinny rail and PRW rings. Sometimes I will use Warne Maxima bases and PRW rings. Just a real nice straight solid solution. The newest thing Is the two piece, ring/mount combo aluminum mounts like the Leupold Backcountry, and the Warne. I really like the 2 sets I have tried.

 

[Ru4real]

With that style mount I center the scopes adjustments and eyeball the rear base to get it centered. If this "eyeball" method hits the target near the center I'll leave it alone and finish zeroing with the scope. Use your judgement about whether (near the center)is close enough for you. I prefer my scope adjustments to be close to centered when zeroed. Thats one of the good things about a Picatinny style rail.

The rear adjustment type of mount has gotten a lot of bad mouthing over the years but I have several rifles with that type of mount that have served me well. I reserve the Picatinny type mount for my Varmint rifles where weight isn't as much of a factor.

The older style Redfield rings with the bottom screws make a classic looking mount on a blue steel wood stocked rifle!

Thanks, that is how I set the rear mount for now. I’m on at 100, and when I shoot farther, if I need windage, I’ll tweak the mount and not the windage knob on the scope.

 

[Ru4real]

If you did the front ring straight and cinched up the rear screws evenly it should be good to go.

Thanks! That is where I screwed up last weekend, I didn’t tighten them down evenly. Yesterday at the range I readjusted but could only check at 100 yards. I’ll tweak it a little when I shoot further I suspect.

 

[berettaprofessor]

Buy one of these: https://www.midwayusa.com/product/1009245523

 

[Legionnaire]

Many years ago a machinist friend gave me a 12-inch length of 1-inch steel rod. When installing a set of Leupolds with a front dovetail and windage-adjustable rear, I tighten the front ring on the rod then turn the ring in so the rod is aligned with the bore. That's pretty easy to eyeball with the 12-inch length. Then slide the lower half of the rear ring into place under the rod and alternately tighten the clamping screws until they just touch the ring. Put the cap on the rear ring and tighten it down on the rod. That makes sure both rings are perfectly aligned. Then tighten the rear clamping screws to recommended torque. Pull the ring tops and remove the rod. Your scope should drop in to the ring halves with no binding. If the scope binds, something isn't aligned properly. Adjust as necessary. Then tighten down the ring top halves.

I've done this on all my hunting rifles with one inch scopes. With the scope optically centered, it's very rare to not have the windage on paper and fairly well centered at 50 yards. The trick with those windage-adjustable rear rings is to get them aligned while keeping the scope optically centered. That preserves the maximum amount of windage and elevation adjustment.

 

[Ru4real]

Many years ago a machinist friend gave me a 12-inch length of 1-inch steel rod. When installing a set of Leupolds with a front dovetail and windage-adjustable rear, I tighten the front ring on the rod then turn the ring in so the rod is aligned with the bore. That's pretty easy to eyeball with the 12-inch length. Then slide the lower half of the rear ring into place under the rod and alternately tighten the clamping screws until they just touch the rod. Put the cap on the rear ring and tighten it down on the rod. That makes sure both rings are perfectly aligned. Then tighten the rear clamping screws to recommended torque. Pull the ring tops and remove the rod. Your scope should drop in to the ring halves with no binding. If the scope binds, something isn't aligned properly. Adjust as necessary. Then tighten down the ring top halves.

I've done this on all my hunting rifles with one inch scopes. With the scope optically centered, it's very rare to not have the windage on paper and fairly well centered at 50 yards. The trick with those windage-adjustable rear rings is to get them aligned while keeping the scope optically centered. That preserves the maximum amount of windage and elevation adjustment.

Thanks! My scope never came out of the rings so ring alignment didn’t change in my case. What you said about optically centered resonated with me. I was wondering how I should get there.

I’m “sighted” in at 100, and my plan was to shoot out to 600. But starting over “optically centered” makes more sense thanks to your comment.

I think that’s what I’ll do. Center the scope turret windage for now, shoot at 25 and adjust the rear ring for windage. Shoot at 100 and adjust the rear ring for windage. Shoot at 600 and adjust the scope turret windage.

 

[Legionnaire]

I recommend not using the scope tube itself to twist/align the front ring. I know it's tempting, but it stresses the scope tube. That's why I scrounged the steel rod. Good luck!

 

[Ru4real]

I recommend not using the scope tube itself to twist/align the front ring. I know it's tempting, but it stresses the scope tube. That's why I scrounged the steel rod. Good luck!

I just checked my “optical center” using full travel of the scope windage and knowing I sighted in at 100 after eyeballing the rear ring adjustment at the range yesterday. I was 5 MOA from “optically centered”.

Thanks again, you saved me a few rounds at the bench!

 

[herrwalther]

Buy one of these: https://www.midwayusa.com/product/1009245523

This is what I use. Good quality rings rarely need to be lapped. So you can save a lot of time by checking alignment before hand.