Mount Up

Mount Up

Scope mounting mistakes can cost you. Here's how to do it right.

Most scope mounting work is straightforward, but even experienced shooters bungle mounting jobs. Not long ago, in a hurry to scope a rifle, I installed the rings without checking height. I'd assumed the front and the rear rings were the same; alas, they were not.

Then, as if to add insult, I botched a second mount job when I didn't realize the base screws were a few threads too long and were bottoming out. Result: I sheared off both screws in the receiver.


And once on an African hunt with a borrowed rifle, the gun's Redfield-style scope base lost its left-hand windage screw. I should've checked the rifle when some shots flew true and some did not, but I didn't. Unfortunately, it cost me some animals.


To prevent these and other problems, attach your scope when you have time to think about what you're doing, where you have good light and no distractions. Like taking an important test, shooting a rifle match or giving a speech, affixing a scope to your rifle is best done early in the day, when you're not tired.

Here's how to do it. Snug the rifle in a rifle cradle. If you don't have a cradle, get one.


Swab the receiver and mount or ring bases with gun-cleaning solvent to remove grease, grit and fingerprints. Follow with a dry cloth, then a silicone-impregnated rag.


Put base screws in a coffee saucer. If you don't, you'll lose one or more. Guaranteed.

Set the base on the receiver and start the screws using a close-fitting magnetic screwdriver tip--the tip only. After screws are seated, add the screwdriver handle and snug them alternately. Check bolt clearance by cycling the action before tightening the screws. If you feel any undue resistance, back off the offending screw and replace with a shorter one or grind to fit.

Before attaching rings or giving base screws a final turn, set your scope on the base to check ring spacing and ensure that you'll get proper eye relief. Variable scopes with short sections of free tube can limit your options. Some scope bases can be reversed to your benefit.

If you don't see how you can place the scope where you want it, consider another base or extension rings. While rail-type bases aren't trim, they typically offer more latitude in sight placement.

Tighten the base screws as if you were paid by the inch-pound but will be docked a month's wages if you twist one off. Loc-Tite is not necessary, in my view. If you wish to lock those threads, use blue Loc-Tite; it allows screw removal more readily than the red version.

Leave Ruger-style rings snug but not tight to the receiver so the scope can self-center.

Separate the rings, using the saucer to hold ring screws. Keep the ring halves paired and the ring ends oriented as they came from the package. CNC machining is supposed to make such matching unnecessary, but it's still a good idea.

Depending on mount design, you'll first affix rings to base or clamp them lightly to the scope tube. Run the ring screws in finger-tight. If the rings are vertically split, heed directions as to the tightening sequence of all screws. You'll want a gap in both ring junctures when the scope is secured. It doesn't matter whether the split is vertical or horizontal; don't let ring halves contact each other.

While the scope is still loose in the rings but the lower ring or ring juncture solidly affixed to the scope base or rifle, slide the scope forward until you get proper eye relief.

Check eye relief prone and sitting, not just offhand. Wear heavy clothes as well as light. Scope position will be a compromise, but you'll want the eyepiece to clear your brow during recoil every time.

Most hunters place the scope too far back for prone or uphill shots, and the ocular ring prints a half-moon between their eyes.

As a rule of thumb, I start with the ocular lens directly over the rear guard screw--after adjusting the focusing ring for a sharp reticle image. Then I mark ring position on the tube with a pencil. It's best to leave 1/8 inch between rings and any junctures in the scope tube.

Next, turn the scope until the vertical reticle wire is lined up with your rifle's buttplate. Use a square or vertical edge or Wheeler Engineering's Level Level Level to check. If the reticle is not plumb, you will cant the rifle and miss at extended range.

Snug ring screws alternately, as you'd tighten lug nuts when changing a tire. Before finishing, see that the gaps between ring halves appear equal. These screws needn't be as tight as base screws. Over-tightening can mar and even deform a scope tube.

Bore-sight the rifle. If your mount base allows you to adjust ring position for windage, run the scope's windage dial to its center position (count clicks from one stop to the other, then come back half that number) and bore-sight using the base screws. That way, you'll keep as much windage adjustment as possible and maintain the erector assembly in the middle of the tube.

Once you've bore-sighted, it's off to the range to get your desired zero.

A careful mounting job should give you confidence in your scope. Honestly, it's rare that modern scope mounts are "knocked off" by incidental bumps in transit or on the trail.

While you're smart to check zero in camp after extended travel, you shouldn't find any change. Just remember to fire a three-shot group before pulling turret caps and fiddling with the zero.

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

All About .300 Blackout

All About .300 Blackout

The .300 Blackout is here to stay, and we take some time to look at new technology surrounding this cartridge. Next, we pit subsonic rivals against each other before stretching the legs of this CQB round out to 600 yards from a short 9-inch barrel.

RS Sako Finnlight II

RS Sako Finnlight II

The new Sako Finnlight II sports an innovative stock and Cerakote metal paired with the terrific 85 action.

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

David Fortier talks with Jeff Hoffman of Black Hills Ammunition about the evolution of the .308 Win. 175 Gr. Match bullet.

Springfield Armory Saint Victor

Springfield Armory Saint Victor

The SAINT' Victor Rifle delivers a lightweight and agile rifle solution while maintaining effectiveness at extended engagement distances.

See More Popular Videos

Trending Articles

SIG SAUER adds to its Elite Match ammo line with the 30-06 Springfield. Ammo

New 30-06 Springfield Elite Match Ammo from SIG SAUER

Rifleshooter Online Editors - April 03, 2019

SIG SAUER adds to its Elite Match ammo line with the 30-06 Springfield.

If you're a serious shooter with deep pockets, these Leica products are worthy of consideration. Accessories

Three Rangefinder Products from Leica

J. Scott Rupp - May 08, 2019

If you're a serious shooter with deep pockets, these Leica products are worthy of...

Wilson Combat's new Ultralight Hunter in .300 Ham'r puts the sport back in modern sporting rifles. MSR

Review: Wilson Combat Ultralight Hunter

Brad Fitzpatrick - March 18, 2019

Wilson Combat's new Ultralight Hunter in .300 Ham'r puts the sport back in modern sporting...

Thompson/Center Arms rimfire rifles are available with Traditional Hardwood and Flat Dark Earth Black Grit finishes. Rimfire

Thompson/Center Arms Adds Stock Options to Rimfire Line

Rifle Shooter Digital Staff - April 16, 2019

Thompson/Center Arms rimfire rifles are available with Traditional Hardwood and Flat Dark...

See More Trending Articles

More Gunsmithing

Bravo Company has you covered if you are looking to build the ultimate AR. MSR

BCM Gunfighter AR Parts

David Fortier - August 28, 2019

Bravo Company has you covered if you are looking to build the ultimate AR.

How to select the right components for your first DIY AR-15. Gunsmithing

The AR Build

David Fortier - December 30, 2010

How to select the right components for your first DIY AR-15.

The Timney Trigger is a rifle upgrade so easy even our editor can do it. Gunsmithing

Rimington 700 Rifle Trigger Upgrade with a Timney

J. Scott Rupp - January 08, 2018

The Timney Trigger is a rifle upgrade so easy even our editor can do it.

The new StraightJacket barrel system delivers on its promises. Gunsmithing

Crazy Performance

David Fortier - October 01, 2010

The new StraightJacket barrel system delivers on its promises.

See More Gunsmithing

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get Digital Access.

All Rifle Shooter subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now