Scopes – Part 2Scope mounts – How well do they need to fit?
by B.B. Pelletier
This is an ongoing tutorial that I hope to turn into a book on scoping airguns. Chapter 1, Part 1 was all the way back in November, and I bet you thought I’d forgotten about this project. I haven’t, but other things kept cropping up. There will be more to Chapter 1, Selecting a scope, but today I want to begin Chapter 2 on Scope mounts.
This subject is daunting to those who haven’t scoped an airgun yet and emotionally charged for many who have. I make no claim to be an expert in this field, but I bet I’ve made as many mistakes as anyone who ever scoped a gun. Through the benefit of those mistakes, I can discuss scoping with you. Today, I want to talk about how the scope fits the rifle – specifically, the width between the dovetails.
Back in 1998, Dan Bechtel, the founder and then-owner of B-Square, enlisted my help in measuring the width of airgun dovetails. He started this project because B-Square was encountering wide variations in the width of what the industry called an “11mm dovetail.” I want to make it clear that I am only talking about straight airgun dovetails, not Weaver or Picatinny dovetails.
Bechtel told me we needed a standardized method of measuring dovetails, because how you measure them determines their width. You cannot simply measure from the sharp point on one side to the sharp point on the other side, because that will tell you nothing about the depth of the dovetail grooves. The depth and the shape of the grooves matters a lot to the fit of the scope mount.
We settled on the method of laying a one millimeter-diameter pin into each dovetail and measuring across from the outside of one pin to the other. I hope the drawing I provided makes this clear to you. Since the one millimeter pin would only go into the grooves so far, we were always measuring the same way, regardless of the angle that was cut into the dovetail.
This mount is made to fit a single air rifle – the Webley Patriot, which is also the Beeman Kodiak. Its clamp is the same one found on all original B-Square adjustable mounts. Notice at the top of the separate clamp, the point isn’t sharp but rounded. It’s a ball end that will pivot in the specially prepared groove into which it fits. Therefore, the bottom of the clamp can extend out farther or in tighter and still fit correctly. However, the gap between the clamp and the body of the mount will not be the same size at the top and at the bottom. This difference disturbs some airgunners and has convinced a lot of them that certain mounts don’t fit certain air rifles correctly. The fit seen here is nearly perfect, but what you see here is not often the case. It only fits this well because this mount was made specifically to fit the Patriot it’s mounted on.
The bottom line
Brownells sells special centers for the precise alignment of scope rings. Many shooters will have their scope rings lapped by a special tool before mounting a scope. Do guns that have had these measures perform any better in the field? Sometimes they do, but often they don’t. A well-mounted scope has more to do with the rifle than with the scope mounts. That doesn’t stop some shooters from wanting things to look right.
Beeman used to sell the SS2 scope with different sets of separator pins to keep the clamp leg parallel to the main mount body. The scope mount was built into the scope, and Beeman understood how shooters worry about the look of their rifle.
If the look of the scope mount bothers you, then get it fixed, because things like that will play on your mind and erode your confidence in the rifle. As you are doing so, however, don’t think for a moment that the appearance really matters. The clamp can be splayed way out to the side, but the gun will still shoot fine. Never underestimate the aesthetics of the rifle. For some shooters, they’re everything.