Scope Mounting (Craig Boddington)

First of all, please note that I didn’t use the title “scope mounting made easy.” I don’t find this chore easy! It is, however, essential to get it right.

Rifle accuracy is a slippery concept; with an unfamiliar or new rifle, you don’t really know what kinds of groupings are possible, or what loads will work best to get the grouping you want. On the other hand, when accuracy is noticeably worse than expected or if a rifle inexplicably shifts zero or won’t come into zero, troubleshooting becomes a process of elimination. A bad scope isn’t impossible, nor is uneven bedding, nor a bad barrel, but the first thing I check are the scope mounts, and they are often the culprit.

Detachable mounts have come a long way in recent years. This is a Leupold detachable, allowing me to have both an Aimpoint red-dot sight and a scope pre-zeroed for this .375. Detachables are usually more complex, and assembly must be correct to attain repeatability.

I am mechanically challenged. Changing a tire taxes my abilities, and mounting a scope approaches my limits. I hate messing with all those tiny little screws; I admit, I tend to break screws and strip screwheads. Although these little mistakes keep my local gunsmith in business, I do manage to do it myself most of the time.

Accuracy is Key

The scope mounts, both bases and rings, are the pieces that tie everything together. They have to be concentric, tight, and right or the rifle cannot produce whatever accuracy it’s capable of. As a gunwriter I do a lot of scope mounting—and remounting, and disassembly. A test rifle comes in, I mount a scope, and I take it to the range. Not infrequently I’ll take that scope off and put another one on. I might use a “sponsor” optic for a TV show, or a new optic I want to write about; often, I simply decide the initial scope wasn’t ideal for the rifle. Lots of reasons, lots of scope mounting. And of course, when it’s time to return the rifle, the scope and mounts usually have to be removed.

Here’s how I do it.

Step One: Tools and Equipment

As far as tools and equipment go, you don’t need much. Over the years I’ve probably had more success mounting scopes at kitchen tables than on proper workbenches. Regardless of where you work, the whole process is a lot easier if you can get the rifle steady and upright (action up). A gun vise is great, but I usually use the uprights on a Tipton cleaning kit or Gun Butler.

There’s nothing wrong with kitchen counter scope mounting. A good stand like this Tipton “Gun Butler” helps, and since I do a lot of scope mounting I keep an array of screwdrivers with various bits on hand.

Next is the only absolute essential: Screwdrivers that fit.

One of my pet peeves is that the various makes of scope mounts have all sorts of different screw heads. It’s enough to drive you nuts! Most mounts come with a simple tool that has the proper bit for that mount. They work fine the first time, but they’re often pot metal and not suitable for multiple uses. I save them—I must have dozens of them by now—but I also have Wheeler screwdrivers, both torque and standard, with interchangeable heads, plus multi-tools.

The simple tools supplied with most mounts work pretty well—at least once—but there’s really no substitute for proper screwdrivers. I got this one from Talley, of course with a bit that fits their mount screws.

I use a lot of Leupold mounts; they make a multi-tool with bits for every screw they use. (Interestingly, there are eight bits on this tool. I haven’t used them all yet, but sooner or later…) I also have a Gun Tool from Real Avid, a clever multi-tool with a dozen bits that cover most scope mounts.

Other than a tube of thread-lock goop there isn’t much more you must have, but I also have both 30mm and one-inch bars for ensuring alignment. These are part of Wheeler’s “Professional Scope Mounting Kit,” which also includes their torque screwdriver with multiple heads, plus levelers for reticle alignment.

Okay, got everything? Put your tools in a well-lit and preferably uncluttered place. Learn from my mistake–there are mount screws in my garage that might surface hundreds of years from now in an archeological dig.

Step Two: Read the Directions Carefully

Once your workspace is ready, the next step is to READ THE DIRECTIONS. Some are very clear, some are not, but read carefully so that you understand the sequence and how the manufacturer thinks their mounts should be assembled. Some brands recommend a thread-locking compound, others do not. Alaska Arms, which offers excellent detachable rings for CZ and Ruger, have some of the best directions I’ve ever seen, including recommendations for torque pressure, screw by screw.

Step Three: Installing the Bases

Once you’ve read the instructions, you’re ready to actually start the job. Generally, the next step is to install bases. This is not universal, however. Some rifles have integral bases; others come supplied with Weaver-type bases or a rail, which is really just a Weaver base on steroids that offers multiple attachment points. A word of caution: If the rifle is supplied with an attached base, don’t assume it’s tight! Make sure the bases are good and tight; I recommend a thread-locking compound to accomplish this.

The good old Weaver mount remains very popular and it works extremely well. The Mossberg Patriot is one of several commercial rifles with Weaver bases supplied. I used the forward base only to install an Aimpoint red-dot sight on this Patriot in .375 Ruger.
Leupold’s Tactical mount is one of the simplest; the base and bottom half of the rings are one piece, so you just put the scope in and tighten the top half of the rings.
The rail mount is essentially just the old Weaver mount on steroids, offering multiple attachment points. Rails are almost universal on ARs, but becoming more common on sporting rifles such as this Marlin .45-70.

 Step Four: The Rings

Obviously, the rings come next, but actual installation is all over the map. All scope rings are split because at some point you have to get the scope into the rings, but some are split horizontally and others vertically. If the rings are split horizontally then the next step is normally to get the bottom half of the rings onto the base; if they’re split vertically then you usually must put the scope into the rings first.

Step Five: Mount Up

There are so many types and variations of scope mounts that I defer to the directions for your mounts. That said, when I was a kid the “Redfield type” mounts with windage adjustment on the rear base and forward ring that turns into a dovetail on the base was extremely common. This mount is still commonly offered by multiple manufacturers; there are variations, of course, such as Leupold’s Dual Dovetail, which features both front and rear rings turning into the base.

The old “Redfield-type” mount, made by numerous companies over the years, is extremely common. The rear ring allows windage adjustment; the front ring turns into a dovetail. The big trick with dovetail mounts is the rings must be absolutely perpendicular to the line of bore.

These mounts aren’t especially tricky, but you need to turn the ring into the base without damaging it—a well-padded wrench works pretty well—and it’s essential to get the rings absolutely perpendicular to the barrel. Doing it by eye really isn’t good enough, and that’s where the Wheeler bar comes into play. A properly-sized dowel can also work. I suppose most of us lay the scope in the bottom half of the rings and do it by trial-and-error, which works, but doing it this way risks scarring the finish on your new scope.

Regardless of how the rings are split, you’ll want to get the scope onto the rifle with the ring screws initially fairly loose so you can still slide the scope in the rings with minimal pressure. This can be tricky, because you don’t want the screws to be so loose that the scope can shift on its own.

The Talley detachable mount is one of my favorites. Like all detachables it isn’t the easiest to assemble, but is very strong and repeatable. Both of these .300 Winchester Magnum rifles wear Talley mounts.

Step Six: Check Eye Relief

Now is the time to check eye relief. Check once more to make sure the rifle is empty, and shoulder it. With the rifle cheeked naturally and normally, you must get a full field of view, and you want as much eye relief as your scope can give you. Scope cuts aren’t fun, and even rifles with very mild recoil can bite you when you shoot from weird positions in the field.

Step Seven: Align the Reticle

The final step before tightening the rings is to get the reticle aligned so the vertical wire is vertical and the horizontal wire is horizontal. This is not easy, and I can’t tell you how many rifles I pick up that have the reticle slightly canted. A scope leveler is probably the best way, but it can be done by eye, checking the vertical wire against a vertical object. Take your time and double-check. If someone else is nearby I usually ask for a second opinion.

It’s very possible to get the reticle straight up-and-down by eye, but also quite easy to be off just a little bit. A level makes it easy…but the action must be straight up and down.

Step Eight: Tighten the Ring Screws

Now we’re going to tighten the ring screws. I do it incrementally, one side and then the other, to even out any gaps. On four-screw rings I tighten in diagonals, a little bit at a time.

Screw tension is important, but don’t go crazy with a torque wrench. Nicely hand-snug is about right. Overdo it and you’ll shear the screw—or strip its head. Either way, it will have to be drilled out which, for mechanically challenged folks like me, means a trip to the gunsmith!

The Wheeler torque screwdriver allows you to set the tension. Especially on ring screws you don’t want to overdo the pressure. They have to be snug, but it you go too far you will break the screw or strip the head. Absent guidelines in the directions, something on the order of 20 pounds of tension is often about right.

I hope I’ve been able to provide some guidance and reassurance. Mounting a scope isn’t rocket science and isn’t hard, but it’s a whole lot easier if you start by reading the directions. Honest!


Craig Boddington is one of today’s most respected outdoor journalists. He spent the past forty years exploring our natural world as a hunter and sharing his knowledge and experiences in dozens of books and through thousands of published articles and essays. He’s a decorated Marine, an award-winning author, and continues to be a leading voice for conservation and ethical hunting around the world. 

For autographed copies of Craig’s books please visit www.craigboddington.com.