How to mount a scope: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

This report covers:

  • What optically centering DOES NOT mean
  • What optically centering really is
  • How to optically center a scope
  • Why do we do it?
  • Field target
  • Counting clicks — mechanical centering
  • Erector tube return spring
  • A better way
  • What about left and right?
  • Why so anal?
  • Pragmatic approach
  • Summary

Today we are going to discuss optically centering a scope. It’s going to be a difficult report for me to write, because the subject does not have much merit for airgunners. So I will compensate by adding some things that do have merit. Let’s go!

What optically centering DOES NOT mean

Let’s start with what optical centering DOESN’T mean. The optical center of the scope is not the place at which there are an equal number of clicks up and down and side to side. I say that and some of you already know it and yet the website “RifleOpticsWorld” has an online article written by “Rifle Optics Team” that says that setting a scope to the optical center is simply returning it to the factory setting. Excuse me????? 

Who in their right mind believes that a rifle scope comes from the factory set to its optical center? The factory assembles each scope as quickly as possible, checks it at certain points for quality and ships it. They don’t spend 45 minutes or more optically centering each scope they make!

This article then proceeds to tell the reader that optically centering is a solution to scope shift! No, it’s not! Optical centering has nothing to do with scope shift and it doesn’t fix it. I will tell you today what really does affect scope shift and how to correct it.

After reading this online article it is obvious to me that it was written by someone (or a team of someones) who was assigned to write it and they made stuff up as they went. If you understand what optically centering is, I invite you to read the article and see how far off the mark it is.

What optically centering really is

The optical center refers to the reticle and the field of view. An optically-centered scope shows zero reticle movement against a distant backdrop when the scope tube is rotated in a complete circle. Theoretically, it’s possible to achieve, but I’ve never seen it. The best I’ve seen is a reticle that moves about a quarter inch against a target 20 yards away when the scope tube is rotated in a complete circle.

How to optically center a scope

There are two ways to optically center a scope. The first way is to set the scope tube in Vee blocks and rotate the scope while watching the reticle against a distant target. I have done this with a quarter-inch dot as the target — set 20 yards from my position. Believe me — it can take a long time to get the scope pointing exactly at that dot — even with two people working at it! The easiest way I have found is to put a large white sheet of paper at 20 yards distance and talk a friend into drawing the dot, while you look through the scope that’s sitting in the Vee blocks and direct him. I initially thought the precision of the Vee blocks mattered, but I’ve since recognized that you can use a cardboard box with two Vee grooves cut in the right place to support the scope tube. It’s not the blocks that give the precision; it’s the fact that, other than rotating on its axis, the scope never moves..

Now, rotate the scope tube in the Vees and adjust the reticles until both lines remain centered on the dot. On a good day with some luck this takes about 45 minutes to get as close as you are going to get and the reticle will still move off the dot in a few places in its rotation, i.e. the intersection will move in and out of the dot as the scope rotates.

The second way to optically center the scope is to stand the objective lens on a mirror in a well-lit room or even outdoors in bright sunlight. Look down through the scope and what do you see? If the reticle appears blurry or doubled, adjust it until all you see is one sharp reticle. In other words, the real reticle is on top of its reflection. This way sounds easier than the first method because it is. But it doesn’t give results that are any better than the first method and maybe not as good. You see, the glass on the mirror is not parallel to the reflective surface on the back of the mirror, and you will always be off by some small amount.

mirror technique
With the scope’s objective resting on a mirror, adjust the horizontal and vertical reticles until the heavy reticles are covering the shadow lines — as best you can.

Why do we do it?

The belief is that once the scope is adjusted to its optical center it can then be mounted in an adjustable scope mount and, without changing the elevation or windage knobs, zero the scope at an ideal distance by adjusting the mount, only. You will have to use a scope mount that adjusts in both directions to do this. Having done this several times I can tell you that it is absolutely impossible to do. But, for the sake of argument, let’s assume it can be.

Once the scope is optically centered and also zeroed, you can then adjust the scope’s elevation reticle for range changes to your target. Because the scope is optically centered, the pellet will stay on the vertical reticle at all practical distances. Let me give an example.

Field target

You have optically centered your scope and then zeroed it at 20 yards by adjusting the scope mount. You are shooting a .177-caliber pellet at 900 f.p.s. You will be on target from 20 yards to about 24 yards and then your pellet will start to rise above the center of the crosshairs. The pellet is not really rising, of course; it just appears that way to you.

From 24 yards to 28 yards the pellet rises until it is one pellet’s diameter above the center of the crosshairs but exactly in line with the vertical reticle. Starting at 29 yards until 32 yards the pellet will descend on the vertical reticle line but still be on the line, left and right. At 33 yards the pellet will start to descend below the center of the crosshair and by yard 35 it will be one pellet’s diameter below the center of the crosshairs.

dime and sight-in
This is the level of accuracy a field target competitor is seeking.

What you have just done is sight in an air rifle that is on target without any scope adjustment from 20 yards to 35 yards. You will be theoretically able to hold on the center of a kill zone on a field target within that range span and hit the paddle without touching the side of the kill zone — on all targets that have a 3/4-inch kill zone or larger.

All that I have just said is theory and it doesn’t work that way in the real world. In the real world the following is true.

1. It is impossible to optically center any scope. There will always be some slight movement of the reticle against a distant target as the scope is rotated through 360 degrees.

2. It is impossible to zero a scope with an adjustable scope mount. You can get close, but never exactly on.

Before we continue, let me define what I mean by exactly on. I mean the pellet is striking the point where the reticle lines intersect, with an equal amount of the pellet on either side of each line. This sounds anal, but the sport of field target makes shooters anal pretty quick. You see, there are kill zones that are smaller than 3/4-inches — some as small as 15 mm. When I competed in the late ’90s they were even smaller than that — down to 3/8-inch (9.44 mm). 

caliper and dime
This is the size (15 mm) of the smallest field target kill zone today.

If your pellet touches the side of the kill zone while passing through it can push the target “face” backwards hard enough to lock it upright, even though the paddle has been hit. The target won’t fall and you won’t get a point. This is the reason field target shooters are so concerned with accuracy.

Once when I was competing, one of the shooters brought his friend to the match to try it. He was a SWAT sniper and was confident he would do well. I think he thought he would teach us all a lesson in how to shoot. He finished in the middle of the pack of about 20 shooters and when it was over he told us that he was trained to shoot someone in the middle of their head. He reckoned that field target shooters would aim for one particular hair on the head — which is just about the case.

Counting clicks — mechanical centering

I hope I have made my point why optically centering a scope is impossible. Later on I’m going to tell you a very practical way to get the result that people desire from centering, but right now let’s discuss mechanical centering.

When you center a scope’s adjustments mechanically you are finding the spot in both adjustment where there are an equal number of clicks in all directions. If there are 123 clicks down there have to be 123 clicks up. Same for left and right, though they may not be the same number of clicks left and right as up and down. But don’t worry — it doesn’t matter, and here’s why.

Erector tube return spring

The reticle lives in the erector tube and the lines never appear to move when adjusted. That’s because they don’t. The entire tube moves while the lines remain stationary. Yes, there are European and Russian scopes whose reticle line actually do move, but they are an exception and not a part of this discussion.

There is a spring that’s mounted on a 45 degree angle to the erector tube and across from bothe adjustment knobs. It pushes back against both the vertical and right adjustments to keep the erector tube in whatever position the adjustments have put it. To the shooter it looks like nothing has moved.

At some point this spring gets relaxed and doesn’t push as hard. Then the tube can move without being adjusted — as in when it is jostled or bumped. That is when the scope starts to lose its zero and shifts randomly. So, centering the reticle (erector tube) mechanically doesn’t make much sense. Yes there may be 123 clicks on upward adjustment but the last 63 of them may be with the spring relaxed, so they are worthless. You don’t want to adjust the elevation there. Now that the scope is mechanically centered you have a lot of good downward adjustment that is useless (because you never adjust the scope that way) with very little upward adjustment before you start experiencing scope shift.

erector tube return spring
When the erector tube return spring relaxes, the erector tube starts moving on its own from vibration. Goobye zero!

A better way

Now I will tell you what really works and what top shooters around the world have discovered. Forget optical centering. Forget mechanical centering. Instead, adjust your scope until there is very little downward adjustment left. Once you zero the scope (with the adjustable scope mount) you will never use any downward adjustment. But you will use the upward adjustment, and this procedure has left a lot of it in the scope.

Everything I just said also applies to left and right adjustment, though it is not as critical. Gravity pulls pellets down; it doesn’t move them left and right.

What about left and right?

Okay, you understand how up and down works. What about left and right? Let’s assume that when you adjust the scope up the pellet stays glued to the vertical reticle. It never moves off the vertical line. It never does, but let’s pretend for a moment that it does. If you haven’t optically centered your scope, what happens when the farther out you shoot the farther the pellet strays to the left? 

Let’s also assume you are using a scope level for every shot, because none of this works if you aren’t. You notice that at 35 yards the pellet is half a diameter off to the left and at 45 yards it’s more than a full diameter off. What do you do?

What you do is check your zero at every 5-yard distance from 10 yards to 55 yards, because that is the distance at which you compete. Yes, I am aware the rules have changed and those distances are now stated in decimal fractions, but let’s keep this simple. And I said you check your zero every 5 yards and keep making small adjustments, but champions will then refine that to every yard — from 10 to 55 yards, or every meter from 10 to 50 meters.

What you do is adjust the left-right setting on your scope to get it as close to the centerline as possible at all distances. You never will get it perfect, but let’s say with careful work you get it to the place where your pellet is one diameter off to the left at 51 to 55 yards and one pellet diameter off to the right at 10 to 14 yards. It’s off by a lesser amount at the intermediate distances. Most field target competitors would be thrilled to have a scope that was that dialed-in.

Why so anal?

Do you really have to do any of this? Of course not. I don’t. You can go right on with your life, just as before. Nothing has changed. I wrote today’s report for those readers who were asking about optical centering. 

Pragmatic approach

The steps I have just given you (the last ones — the ones that really work) can take DAYS to complete! If you always want to see the bullseye get hit, watch a movie. This level of commitment to perfection is why some scopes cost more than $3,000 and some mounts cost over $500. You would be fooling yourself to think that serious competition can be done without a serious investment. Yes, you can follow these steps and do quite well on a budget, but remember — nobody races real cars in NASCAR.

My way is hard work. All the theory is out the window. As Jedi master Yoda told us, “Do, or do not. There is no try.”

Summary

In this article I have given you lots of things to do. But at their core there is one piece of invaluable advice. That is — it is impossible to do any of these things exactly. That applies to all of the procedures and desired results I have presented. You may think you are a perfectionist, but also recognize that for human beings there is no such thing.

You still should do your best to get as close as you can — so close that your hard work becomes a humorous anecdote that you can tell for many years to come, as I have just done for you!


How to mount a scope: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • The olden days
  • What needs to be done
  • Eliminate cant
  • The tale
  • More information
  • The scope must be angled down
  • Adjusting the scope too far right is also bad
  • Not experts
  • Position the eyepiece
  • Adjustable scope mounts
  • Is it enough?
  • Points to remember
  • Summary

The olden days

When I started shooting in the 1950s, scopes were not that common, especially on airguns. I was as intrigued by them as anyone, believing that they increased the accuracy of whatever they were mounted on. 

Well, they don’t. What they do is make it easier to shoot accurately with a given airgun or firearm. But they can only do it if they are mounted on the gun correctly and then sighted in properly. This series is dedicated to addressing all that is inherent in both mounting a scope correctly and then sighting it in properly.

What needs to be done

To properly mount a scope there are several things to consider. Here is a list.

  • Secure mounting
  • Proper eye relief
  • Angle the scope so the elevation doesn’t have to rise above halfway
  • Align the optical axis with the boreline
  • Eliminate cant

I have written more than 30 reports on scope mounting since March 3, 2005, when this blog started. I will draw on them as I go, but I’m also going to break some new ground. Not that scope mounting has changed, but B.B. Pelletier has changed over the years. He has gained experience!

Eliminate cant

Canting is a subject all by itself. I won’t deal with it today.

The tale

To tell this story I will begin with a tale that happened to me a week ago. A friend from church told me the scope on his Gamo breakbarrel had broken — that the crosshairs are now sitting cockeyed

cockeyed reticle
When the scope is still mounted tight on the air rifle but the reticle looks like this, the scope is broken.

More information

In our second conversation he told me something more. He said his scope wouldn’t hold its zero. Right away I knew what the problem was. The scope’s elevation was adjusted too high and the erector tube return spring had relaxed, allowing the erector tube to bounce around as the rifle recoiled, and also vibrated, as I discussed yesterday.

erector tube
The erector tube inside the main scope tube contains the crosshairs. When the scope is adjusted this tube is what moves. The crosshairs remain in a constant position and only move because the entire tube moves. The erector tube is also where the magnifying lenses are.

Where the reticle assembly is located in the tube makes a difference. If it is at the front of the tube it is called a first focal plane scope and because the erector tube is what magnifies the image, the reticle enlarges as the power is increased. If its located at the rear of the tube the reticle remains the same size regardless of magnification and that is called a second focal plane scope.

The scope must be angled down

What most rifle owners don’t know is the axis of their barrel points down. It is not aligned with their receivers, despite what they believe. This is so common on the AR-15 that special scope mounts with a down angle have been created. If you search the internet you’ll find AR-15 owners complaining that their expensive scopes and mounts won’t hold zero and they are getting lots of advice to change the scope and mounts. The problem is — the advice they are getting is all wrong. They have a barrel droop issue and have adjusted their scope’s elevation too high.

I have been at the range when a guy with an AR was sighting in. He had his elevation adjusted up past the 3/4 mark, which he had to, to get on target at 100 yards. The scope will never hold a zero when adjusted that high. He was shooting 4-inch groups before I had him adjust the scope down 60 clicks. Then his groups shrank to around 1.5 inches. Of course they were too low, but that can be fixed. Let’s get back to airguns.

When I examined the mount of my friend’s Gamo Whisper rifle I found a deep scratch along the top of the aluminum scope base on the rifle. Whoever mounted the scope, and I am guessing it was done at the factory, did not put the scope stop pin inside the hole in the scope base. Constant recoil and vibration caused the steel stop pin to slide along the top of the scope base and dig a deep furrow.

scope base
Whoever mounted the scope didn’t put the stop pin into the hole in the base. They just tightened it down as tight as it would go with the subsequent sliding along the base from recoil over the years.

scope stop pin
This scope stop pin on the bottom of the one-piece scope mount of the Gamo Whisper should have been placed in the scope base hole, not tightened against the top of the base.

Adjusting the scope too far right is also bad

Adjusting the scope’s elevation too high is bad and the same holds for adjusting the scope too far to the right. The erector tube spring relaxes and the tube starts moving under recoil. But too far to the right is rare because it’s easy to see, where the droop is harder to detect.

Not experts

This is where buyers sometimes miss the boat. They think that if the company that made the rifle also mounts the scope it has to be done right. They don’t appreciate what goes on in those companies — that someone with little or no training is given the task of installing scopes on rifles. They certainly don’t then shoot each rifle to test their work. Some will mount them right and others won’t.

Now, if a retailer like Pyramyd Air mounts a scope they do it right because it’s their name on the line. I used to scope rifles for customers when I worked at AirForce Airguns. I did take the time to zero each of them, which is how I came up with the 10-foot sight-in process that I wrote about.  And I gave the 5-shot group I shot to the customer, so they knew how well their rifle could do. But that kind of service is the exception rather than the rule. What we see here — the mis-mounted scope mount and no regard for barrel droop is more common.

Position the eyepiece

Another complaint my friend from church had was the eyepiece of his scope was positioned too far forward. All he saw was a small image instead of the full image the scope is supposed to show. So I also took care of that when I mounted his new scope. 

Adjustable scope mounts

The best solution to a rifle that droops is to mount the scope on an adjustable mount. It’s expensive but my vote goes to the Sportsmatch scope mount that can be adjusted while the scope is on the rifle. But a guy spending $275 on a breakbarrel bundle isn’t going to pop for $150 more just for a scope mount. So my less expensive solution is to shim the scope under the rear ring.

shimmed scope
There is the shim I put under the scope on the rear ring. It’s a cut-up credit card.

shimmed scope angle
And this is what that one shim did. The scope base is level. The scope is slanted on a downward angle that’s visible, relative to the scope base.

When you tighten the ring caps don’t tighten them too tight or the scope tube will bend. When it’s shimmed it’s no longer cradled in the ring that’s designed for it. The new angle will help keep it from moving in the rings during recoil, so the caps don’t have to be as tight.

Is it enough?

Is what I did enough? We won’t know until the rifle is sighted in and tested. That job falls to its owner, though I stand ready to help if he needs anything further.

Points to remember

  • Most rifles shoot down and need their scopes mounted to compensate for it.
  • Scope rings need to be mounted to the scope base correctly if they are to do their job.
  • If a scope’s elevation is adjusted too high the scope may not hold a zero. Same if it’s adjusted too far to the right.
  • Don’t over-tighten the scope caps when the scope is shimmed.

Summary

That’s it for this report. If I’ve left something out or not explained it well enough, let me know.


John Wayne Lil’ Duke BB gun with scope: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Lil Duke and scope
John Wayne Lil’ Duke BB gun with scope.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • What happened?
  • I thought I knew better
  • HOWEVER
  • Is it really tight?
  • The scope
  • The test
  • Air Venturi Steel BBs
  • Hornady Black Diamond BBs
  • Avanti Match Grade Precision Ground Shot
  • Smart Shot
  • Old Dust Devils
  • Dust Devil Mark 2
  • What have we learned?
  • Summary

I tested the John Wayne Lil’ Duke BB gun with scope in Part 4, but if you read that report you’ll see that the scope base was a little loose. Today’s report clears that up.

What happened?

Reader Chris USA asked me if I read the instructions that came with the scope base, Of course I read them. The better question to ask was when did I read them? I read them as I was editing my report and wondering why Pyramyd Air would let a scope base this flimsy go out. That was the reason for the Oh, fudge! title at the end.

I thought I knew better

You see, I tested a BB-gun scope base like this back in 2016. You may remember the Brice scope base for the Red Ryder BB gun. That was years before this base hit the market and I thought I knew everything there was to know about BB gun scope bases.

And, by the way, Chris, that is the scope base Tyler shows in his video. He is mounting a scope to a Red Ryder — not the Lil’ Duke. That base has the acorn nut. This one for the Lasso scope on the Lil’ Duke does not. Nor does it have two screw holes in back for mounting the scope that are shown on the description page. Look at the picture I showed you in Part 4. That is the base I am testing. It has one screw hole and no acorn nut.

Duke scope base
This is the scope base that comes with the Lil’ Duke. It has a single screw hole.

HOWEVER

I told you the one screw that screws into the top of the pistol grip and holds the scope base tight is important. It’s a machine screw — not a wood screw like you might assume. I had screwed it in many turns and it never got tight. I thought it was not long enough to grab the threads in the stock, but now that I was fiddling with the base again I turned it many more revolutions and it finally tightened. I just had not turned it in far enough! That’s the difference between a wood screw with fast threads and a machine screw with finer threads. With the screw tight the scope base also got reasonably snug, though not what would call tight.

But there is more to it. I showed you a picture of the scope base installed without the rear sight elevator back in the sight. In the caption I said the elevator is supposed to be in the sight. When do you think I wrote that caption? That’s right — after writing the Oh, fudge title for that paragraph! Yes — as difficult as it is to believe, even for me, old BB Pelletier messed up big time!

As it turns out, that elevator is very important to the mounting of this scope base. It raises the rear sight leaf, putting downward spring tension on the scope base. Voila — the scope base is now tight!

Duke elevator
The rear sight elevator puts downward pressure on the scope base, tightening it when the rear mounting screw is tight.

Is it really tight?

Now that I have corrected the scope base, is it really tight? Yes and no. It’s tight if no pressure is put on the scope tube. But it is still possible to wiggle the scope from side to side just a little. The base is plastic and I see no way around some movement because plastic flexes. But it seems to return to the same position after each wiggle. I think the accuracy test will determine whether it is solid or not.

The scope

Since I was perfecting things I also spent time with the Lasso scope. I unscrewed the eyepiece close to a half inch and finally got the reticle lines sharp. The target is still not in focus, but that is a problem with the fixed parallax that I will live with. It isn’t that bad.

The test

I ran another accuracy test from 5 meters, resting the BB gun on the UTG Monopod as before. I shot 10-shot groups as before and I shot the same BBs that were used in the first scope test in the same order, so we can compare groups.

Though the scope has been taken off the gun and the mount tightened, I still sighted in from 5 meters because that is very close. I shot the first group that landed low and right. I attempted to adjust the scope up, but it was already up as high as it would go. If I really wanted to use it I would put a thin washer under the base before screwing it tight. A shim under the rear might raise it up to the aim point.

Air Venturi Steel BBs

At 5 meters 10 Air Venturi Steel BBs went into a horizontal group that measured 1.905-inches between centers. In the previous test the group size was 2.385-inches, so this is 0.48-inches smaller. It’s a good start.

Duke Air Venturi group
Ten Air Venturi Steel BBs made this 1.901-inch group at 5 meters.

Hornady Black Diamond BBs

Hornady Black Diamond BBs were next to be tested. In the previous test ten BBs went into 1.814-inches. This time ten went into 1.662-inches — a difference of 0.152-inches. That’s really too close to call.

Duke Hornady group
Ten Hornady Black Diamond BBs went into 1.658-inches at 5 meters.

Avanti Match Grade Precision Ground Shot

In the previous test ten Avanti Match Grade Precision Ground Shot made a 1.711-inch group at 5 meters. In this test another ten of the same BB went into 1.096-inches. That is 0.615-inches smaller, which is significant. It’s less than half the size of the previous group.

Duke Avanti Shot group
The scoped Lil’ Duke put 10 Avanti Match Grade shot in 1.096-inches at 5 meters.

Smart Shot

Now we come to the BB that has proven itself to be the most accurate one in this gun — the lead H&N Smart Shot. In the previous test 10 made a 1.148-inch group with one shot that was a pull. This time 10 went into 1.327-inches at the same 5 meters. Yes, nine of them are in a much smaller 0.952-inches, but the shot that is out to the right was not a called pull, so it is a legitimate part of the group. In this case, the previous group was better than this one by 0.179-inches. That is almost enough of a difference to be meaningful.

Duke Smart Shot group
Ten Smart Shot lead BBs made this 1.327-inch group at 5 meters.

Old Dust Devils

Next to be tested were the Old Dust Devils that are no longer available. In the last test ten made a Ten of them made a 1.147-inch group at 5 meters. This time ten went into 2.128-inches at 5 meters. That is considerably larger by 0.981-inches! I cannot explain why this group is nearly twice as large as the one from the former test.

Duke old Dust Devil group
Ten of the old Dust Devils went into 2.128-inches at 5 meters.

Dust Devil Mark 2

The new Dust Devils did okay this time. In the previous test 10 went into 1.345-inches at 5 meters. In this test ten made a 1.469-inch group at 5 meters. That is a difference on 0.124-inches in favor of the previous test. Once again, not a very significant difference.

new Dust Devil group
Ten new Dust Devils went into 1.469-inches at 5 meters.

What have we learned?

I hope the big lesson today is to both read the manual and also spend time with the gun as you mount the scope base and scope. I don’t care for scopes on BB guns, yet this one seems to do okay except for being out of focus and shooting too low.

I think all the testing has proved beyond any doubt that the Smart Shot BB is the most accurate in this gun. It has also demonstrated that this little BB gun is remarkably accurate with many BBs, and should be on your short list as an ideal kid’s BB gun.

Summary

The Lil’ Duke is a winner! With the open sights it’s the most accurate lever action spring piston  BB gun I have ever tested besides the Daisy 499. If you need a BB gun, this is the one to get.


UTG 4-16X44 OP3 Compact scope : Part 1

by Tom Gaylord
Writing as B.B. Pelletier

UTG 4-16 OP3 Compact
UTG 4-16X44 OP3 Compact scope.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • Huh?
  • Pyramyd Air Cup
  • What makes this scope special?
  • The reticle
  • Reticle adjustments
  • True Strength scope tube
  • Sidewheel parallax adjustment
  • Bright optics
  • Compact
  • Rings included
  • The plan
  • Summary

Huh?

Okay, Lucy (from the TV series “I Love Lucy”) got some ‘splainin’ to do. Why is today Part One of a report on the UTG 4-16 AO Compact scope and yet there are links to Parts 1, 2, 3 and 4? Well, those links all go to the FX-Dreamlite that I last tested in July. At the end of Part 4 I said I had more to test, and this is the start of it.

As you know, the Dreamlight that I tested had problems delivering the accuracy we expect from an FX. It has the Smooth Twist II barrel, which we discovered is very pellet-specific, but I still have not tested it with a good range of pellets it likes — especially the heavier ones. I told you way back in July that there was more to test and today is the start of it.

I Part 3 I had mounted a UTG 8-32X56 SWAT scope on the rifle and went through the horrendous problem of sighting it in. Because the Dreamlite that I am testing is a super drooper I had a hard time getting it to zero. But I did zero the rifle and also shot some groups. Now I want to continue testing this rifle with today’s new UTG scope.

Pyramyd Air Cup

While I was at the 2019 Pyramyd Air Cup this year, the guys from Leapers showed me a brand-new second focal plane UTG scope — the one I am reporting on today. I was stunned by its clarity. That remark deserves some explanation, because it’s the same thing I said about the new Meopta Optika6 scope I just finished testing on the S510. While I don’t compare products, one to another, I will tell you that the Optika6 is a clear winner for clarity. But, by how much? And, are you willing to pay $650 for that edge, when this beautiful new scope costs $230? I bought the Meopta to have at least one scope that compared to a $3,000+ scope. But this UTG is hands-down the clearest scope you will see at this price or even perhaps a hundred dollars more.

What makes this scope special?

This isn’t the first 4-16 power scope you have seen. That range of powers is a wonderful blend for a lot of different shooting including plinking, hunting and some target shooting. There are many other scopes with a similar power range on the market, so what makes this one stand out? Here we go.

Etched reticle
MOA reticle
Illuminated reticle
True Strength scope tube
30mm scope tube with 44mm objective lens
Sidewheel parallax adjustment from 10 yards to infinity
Zero-lockable turret knobs
Low target turrets that adjust in MOA
Compact scope body

The reticle

Like I said, this reticle is etched on glass, so it stays clear and sharp. The illumination only lights up the central cross, which is perfect for hunting in low light because there is no flareup reflection on the inside walls of the scope tube. Plus, the EZ-Tap reticle has 36 potential colors and brilliances, so there will always be a color and intensity to suit the situation. And the illumination stays on until you turn it off so you aren’t fiddling with it all the time. Press either button for two seconds to turn it off.

The reticle is a sort of duplex with a marked MOA cross in the center to help with rangefinding and shot adjustment. The reticle has hash marks that are two MOA apart on both lines. These help a shooter get on target without adjusting the scope. You just move the hash mark where the pellet is striking over to your target. Field target shooters do it all the time on windy days.


This is the OP3 reticle. Both the elevation and windage are marked in MOA. Only the small cross in the center is illuminated. This image courtesy of Leapers.

Reticle adjustments

The reticle adjusts via lower knobs that are also marked in MOA. The clicks are very muted. I can’t hear them but I can just feel them. Fortunately for me they correspond to the markings on the scale, so a visual inspection of that scale is the most accurate way to keep track for me. The locking rings are smooth and positive. And you can loosen the adjustment knobs and turn them to zero on each scale after the scope is sighted-in. An Allen screw on the edge of each knob is loosened for this.

UTG OP3 reticle adjustment
Here you see how the reticle adjustment knobs are marked. You can also see the screws that are loosened to slip the adjustment knobs to zero.

True Strength scope tube

UTG’s True Strength scope tube is machined from a solid aluminum billet. Unlike some scopes with tubes made from parts that are pressed together, True Strength tubes are solid. That means the scope is extra rugged, and Leapers tests for this with Mil Spec shock tests.

Sidewheel parallax adjustment

Of course this scope has the parallax adjustment on the side. UTG has been an industry leader in putting it there. Perhaps you don’t understand why it is in that location. You only have to hold a heavy rifle with one hand one time while trying to reach out to the objective bell to adjust to appreciate why it’s there This is something airgunners did first and best. Just 5 years ago the firearm industry was doing backflips over this “new” innovation that we have enjoyed for more than two decades.

Leapers also sent along an 80mm adjustment wheel that I will attach, once the scope is mounted and zeroed. That’s the way you want it, because not only does the larger wheel give you more purchase for adjusting; if you re-calibrate your personal scope, a larger wheel gives more space for accurate yard markers. Not that a 4-16 scope is used for rangefinding very much, but hunters should appreciate it.

Bright optics

UTG scopes have always been bright and this one is no exception. The 30mm scope tube means the lenses inside the scope can be larger and the 44mm objective lens allows a lot of light to pass through. Of course when the light gets real low you can always do better when a lower magnification is selected.

Compact

This is one of the most attractive features. All this performance comes to you in a compact package. I have 4-16 scopes that weigh a pound more and are a good 4-inches longer. This scope isn’t quite in the Bug Buster class, but it isn’t a lot larger. It weighs 21.5 ounces and is only 11-1/8-inch long. It’s the size of a 4-power scope from 20 years ago. Now, that can be a good thing but also cause some concern. The length of the scope tube where the rings attach has to be shorter to keep the overall length down. That can make mounting on some airguns a little tricky. Tomorrow I will show you how I mounted it on the FX Dreamlite which is one of the most challenging PCPs to scope because of the tall 21-shot magazine that sticks out high above the top of the receiver.

Rings included

The scope comes with two Max Strength Picatinny/Weaver rings. If you want to mount it to an 11mm dovetail be sure to pick up a set of UTG 11mm (3/8″) Dovetail to Weaver Adapters.

The plan

The way I plan to test this new scope is to shoot the Dreamlite at 25 yards with pellets we have already seen tested. The first scope was a 32 power, so this 16-power will be challenged. But I did it with the 3-16 Meopota scope and I believe this one can do it as well. That will also give me a good idea of how sharp the image really is.

After we see that I plan to test the Dreamlite with other premium pellets to see if I can find a second one that’s good in this barrel. This UTG scope will stay mounted for that test, too.

Summary

It looks like UTG has brought out another great scope that we need to be aware of. The size is convenient, the features are impressive and if the performance bears out, we will have another excellent scope to consider.


Daisy model 105 Buck BB gun: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Daisy Buck
Daisy Buck BB gun.

Part 1
Part 2

This report covers:

  • Little Buck Rail
  • Mounting the rail
  • MIL STD 1913 Picatinney rail
  • Weaver rings
  • Won’t the ring move around?
  • What scope?
  • Discussion
  • Summary

We have now looked at the Daisy model 105 Buck BB gun. We’ve seen its velocity and we have seen its level of accuracy with the factory open sights. Today we begin to look at the reason for the report. Today we look at mounting a scope on the gun, using the Little Buck Rail from Buck Rail.

Buck Rail
The Buck Rail is a synthetic adaptor that fits a Daisy Buck BB gun to provide a MIL STD 1913 Picatinney rail for mounting an optical sight.

Little Buck Rail

The Little Buck Rail is an adaptor that fits over the rear sight on the BB gun. It has a hole at the rear for the wood screw that fits the top of the pistol grip on the BB gun.

Reader Terry Harman asked if I would be interested in reviewing the scope base his company makes. I had already tested a scope base for the Daisy Red Ryder back in 2016, and there was enough interest that I thought I would see what Terry’s company makes. I’m glad I did because it is very different from the previous mount I tested.

When I first saw the rail I wondered how it had been made. It wasn’t machined yet the angles and cuts were precise. Then I read the website and discovered that it was printed on a 3-D printer. I think this is the first time I have seen a 3-D printed part sold for retail. I’ve seen plenty of them used for testing, but never as the finished product. Let’s take a look at the design.

One end fits over the Buck’s rear sight. But it isn’t a simple slip fit. There is engineering involved so the fit is solid, once the part is in place. Let’s look at it.

Buck Rail end 1
The Buck’s rear sight slides up into that slot you see here, but it isn’t just a simple slip fit. There is a ledge at the base that presses against the rear sight once it’s in the slot, so the fit is very tight!

Buck Rail end 2
You’re looking at the rail from the other side in this view. The rear sight fits into the slot (arrow) and here you can see the ledge (the arrow passes through it) that presses against the sight.

Mounting the rail

To mount the rail on the Buck you first need to unscrew the Phillips wood screw located at the top of the pistol grip. Remove the screw from the gun.

Next, the rail is positioned over the rear sight like a lever or a shoehorn and the rear of the rail is pressed down. That fits the rear sight into the slot at the front of the rail.

Buck Rail install 1
This is how the Little Buck Rail fits on the gun, but not how the rail is installed.

Buck Rail install 2
Here you see the rear sight slipping up into the slot on the front of the rail. Press the rear of the rail down and the slot fits tight around the rear sight.

Buck Rail install 3
The rail has been pressed down onto the top of the gun. Now the wood screw fits through the hole in the rear of the rail and screws back into the top of the pistol grip.

Buck Rail install 4
The hole in the rail that the screw passes through has a recess for the head. So when the screw is down all the way the head is out of sight.

The wood screw is not going back into the gun’s stock as deeply as it was before. But the taper of the screw shaft is very gradual, so there will be plenty of wood for the screw to grasp. Just don’t tighten the wood screw too much or the hole will strip out.

Buck Rail install 5
The rail is now tight against the top of the gun. It’s ready to accept scope rings.

MIL STD 1913 Picatinney rail

When I examined the rail I thought it was probably an exact MIL STD 1913 Picatinney rail — not a close copy that you see on many scope rails today. MIL STD 1913 is an interface MIL STD. It describes the fit that any scope or optical sight mount must attach to. The thing about it is you are going to need scope rings that will attach to a real MIL STD 1913 scope rail. Just be aware there are many that won’t do it — even though their packaging says they are for Picatinney rails.

To illustrate what I mean, I measured one of the slots that cut across the rail. It should be 5mm in width. Let’s see.

Buck Rail slot width
I’m measuring the width of one of the rail’s slots. They are supposed to be 5mm.

When I saw this measurement I figured the MIL STD specifications had been used in the 3-D printer to create this rail. That’s easy enough to do. Well, that is where some scope rings that don’t exactly meet spec will have problems.

The first scope mount I attempted to install on the rail did not have legs long enough on both sides to reach down over the rail and clamp. I spent 45 minutes with this ring set, thinking I was doing something wrong, before realizing the ring was not really produced to MIL STD 1913.

Oh no, the sky is falling.! Now we need an expensive set of scope rings!

No — you don’t. I decided to show you how easy this really is.

Weaver rings

I selected a set of medium height Weaver rings. Weaver rings have a specification that the width of the rail base is identical to MIL STD 1913. But the cross slot is 3.8mm — not 5mm. That means Weaver rings will fit a Picatinney rail or base, but the reverse is not true. So I took the El Cheapo ring set I found and measured its crossbar for you. Remember, the cross slot is 3.5mm.

Weaver crossbar width
I’m measuring the width of the crossbar under this Weaver ring. It will fit into a Picatinney rail with room to spare.

Won’t the rings move around?

Since the crossbar is smaller than the slot, won’t the rings tend to move back and forth on the rail? No. In a centerfire rifle, recoil will keep the ring’s crossbar or key butted up firmly against the back of the slot. On a BB gun, the ring can be held in place by clamping pressure, alone, as it would be on a rimfire rifle. This is why you can use Weaver rings with Picatinney bases. I wrote a whole report on this 14 years ago.

What scope?

For this BB gun you need a scope that won’t be out of focus at close distances, because BB guns don’t shoot that far. That means either low power or a scope that focuses (parallax adjusts) very close. And we all know there is one scope that adjusts closer than any of them — the Bug Buster! It focuses down to 3 yards or 9 feet. I selected a Bug Buster 3-12X32 for the test. It had a UTG 80mm Sidwheel add-on already mounted and I thought, “What the heck? As long as we’re scoping a BB gun, let’s have some fun.”

The scope mounted in the one-inch Weaver rings easily enough and when I was finished I had something I never thought I would see — a scoped Daisy Buck!

Buck scoped
The Daisy Buck is scoped and ready to go!

Discussion

A lot of thought went into this scope rail, and while I do not believe new shooters should be allowed to use a scope until they can use open sights, that’s just my opinion. Plenty of people want to scope their guns, even their BB guns. I remember back in the 1960s, I would have scoped my BB guns if I had the money. I thought scopes meant more accuracy, period. I think a lot of people today believe they do.

In the test I did scoping the Red Ryder, the gun actually was more accurate with the scope. So maybe this is a good thing. All I can so so far is this Little Buick Rail is certainly well thought out and seems to be well made.

Summary

We have the baseline on the Buck with open sights. Accuracy with a scope is next. And given the scope I am using, I think the Buck is getting its best chance to shine.

There is one more thing I want to show you, but it will come in the next report. I can’t wait to hear what you think!


Smith & Wesson model 77A multi-pump pneumatic air rifle: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

S&W 77A
My S&W model 77A rifle. The black paint is flaking off the aluminum receiver, but the steel and wood parts are both in good condition.

Part 1
Part 2
Part 3

A history of airguns

This report covers:

  • Number of pumps?
  • Scope
  • Bug Buster?
  • Rings
  • Sight-in
  • The test
  • First Hobby group
  • Second Hobby group
  • Discussion
  • Eley Wasps
  • “Oh, somewhere in this favored land the sun is shining bright…”
  • Summary

I have what will be a quick report today, but it will also be one of great interest, I think. This will be my last look at the Smith & Wesson 77A multi-pump pneumatic unless I refinish it.

Number of pumps?

Reader Pgray said he had found a manual for this rifle online that said not to exceed 20 pumps. We were already hearing from several sources that 20 was the maximum, but this came from a manual, so I felt I had to test it for you.

Remember, the RWS Hobby pellet had gone 631 f.p.s. with 14 pumps. So today I tested the same pellet with 20 pump strokes. I only shot three shots, because I still think 20 pumps is a lot for a rifle as old as this. Here is what I got.

Shot……Velocity
1………….684
2………….690
3………….700

I checked the gun after each shot and no air remained in the reservoir. Looking at that short string, it seems to me the pump seals are warming up. I bet if I was to shoot 10 shots the average would be in the low 700s. But I’m not going to do that. Now we know, and that’s enough.

Scope

Several of you felt the rifle deserved a scope, so I mounted one and that’s what I will shoot today. The scope I mounted is one you cannot buy today. I have found it to be a superior scope for many special applications, including scoping this 77A. It’s a UTG 1.5-4X28 scope with a 100-yard fixed parallax. But with just 4-power who cares where the parallax is set?

The closest you can get to the scope I used is the UTG 1.5-6X44 scope. Both scopes have a generous eye relief that allows flexible scope positioning on the rifle.

Bug Buster?

Why didn’t I mount a Bug Buster scope? Simple — it didn’t fit. The places on the scope where the rings have to attach are much closer together than the 11mm dovetails on the rifle. I might have been able to make it work with offset scope rings, but I didn’t want the fuss. And the scope I selected is one of my better optics.

Rings

The scope has a 30mm tube, so I selected UTG POI rings with 11mm bases. I shimmed the rear ring with a piece of credit card to elevate the rear and I didn’t tighten the rings too tight to keep from damaging the scope tube.

SW 77A scoped
The 77A scoped. I didn’t have to use high rings, but when it was time to shoot the scope eyepiece was where I wanted it to be.

Sight-in

The first shot from 12 feet hit the target at 6 o’clock on the bull. So I backed up to 10 meters and shot again. It took a total of 5 shots to sight in the scope. However, I felt the Hobby pellets might not be accurate enough to sight in with less than 5 shots (in other words, shoot a group). I just got that feeling while sighting in.

The test

I shot from a rested position at 10 meters. I pumped the rifle 6 times for each shot. The rifle was rested directly on a long sandbag rest with a second rest under the buttstock. So the rifle was absolutely still for every shot.

With the scope mounted it was impossible to hold the rifle the way I wanted during pumping. I held it back at the top of the pistol grip. If it wasn’t so easy to pump this would have been a problem.

First Hobby group

The first group of Hobbys showed me the rifle was still shooting a little to the right after sight in, though the elevation seemed okay. Five Hobbys went into 0.75-inches at 10 meters. That’s three-quarters of an inch.

SW 77A Hobby 1
The 77A put 5 RWS Hobbys into 0.75-inches at 10 meters when scoped.

After seeing that first group I adjusted the reticle three clicks to the left and shot a second group.

Second Hobby group

The second group of Hobbys measures 1.134-inches between centers, with four of the five in 0.613-inches. That one high shot was the third in the series of five and I watched it fly up there with a mind of its own. So, in my mind the closeness of the other 4 shots is pure luck.

SW 77A Hobby 2
The second time five more Hobbys made this 1.134-inch group at 10 meters, with four in 0.613-inches.

Discussion

At this point it was obvious that a scope didn’t really make any difference. I had gotten all the accuracy from the rifle and this pellet with iron sights. And that’s good because I don’t like scopes on multi-pumps. Unless they are something special like the Daystate Sportsman Mark II I once owned or a Seneca Aspen that is made for a scope, multi-pumps don’t need scopes.

Eley Wasps

I wondered whether a different pellet would help? Now that there was no question about the sights was the perfect time to see. I had thought after Part 3 testing that an oversized pellet might grab the rifling better. What is the largest .22-caliber pellet I have? The 5.6mm Eley Wasp. The next group would be shot with Wasps.

“Oh, somewhere in this favored land the sun is shining bright…”

The first Wasp went into the bull at 7 o’clock. How about that? I was right! Then shot number two hit at two o’clock, an inch and a quarter from the bull. No, I wasn’t right. In the end, five Wasp pellets crowded into a tight 2.234-inches at 10 meters. I could probably do better with a slingshot while spinning on a barstool!

SW 77A Wasp
Where is the inside of that barn when I need it? Five Eley Wasp 5.6mm pellets are in a super-tight 2.234-inches at 10 meters.

But there is no joy in Mudville — mighty Casey has struck out!

Summary

In the end what we have in the S&W 77A multi-pump is a horse of a different color. For a multi-pump it’s solidly built, powerful and unique. But this one isn’t accurate — at least not with the pellets I have tested. I remember that at the same time this rifle was produced some of the Crosman barrels were also a lottery. The barrels on their 160 and 180 CO2 rifles were usually pretty good, but the tubes on the 140 and 1400 multi-pumps were always a gamble.

I could keep on testing different pellets, and perhaps I will, but unless one proves stunning, I won’t show it to you. I am finished testing this rifle.


Aligning a scope with the axis of the rifle bore

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Texas Airgun Show
  • The question
  • The bad news
  • Details
  • The barrel
  • Is the scope base parallel to the axis of the bore?
  • What about side-to-side?
  • Scope mounts
  • The answer
  • Greater precision?
  • However…
  • Close enough
  • What is meant by tweaking?
  • Never perfect
  • Summary

Texas Airgun Show

The 2019 Texas Airgun Show will be held on Saturday, June 22. Here is the website with information. This year they will offer FREE TABLES for people bringing a few airguns to the show! In the tent outside the entrance to the hall there will be several tables that are available to people who bring several of their guns but don’t have tables. These are the guys who normally walk the show holding onto airguns they want to sell and trade. You can now put those guns on these tables for free. There will be lots of table sharing going on, and you need to bring everything you need, because these tables are bare. This has never been done at an airgun show before and the promoters are hoping it will help those carrying their guns around to lighten the load.

Now on to today’s report.

The question

I have a Godfather of Airguns webpage, and sometimes people who read this blog ask me questions there because I guess they can’t figure out how to post them here. Today’s question comes up a lot and is worth a discussion. Here is the question.

“I have a question about the axial symmetry of scope mounts.

“Recently I bought an HW50S and I was looking for a scope mount. I decided to buy a BKL 263 two-piece mount because someone told me that this mount is perfectly centered to the axis of the airgun rail, and will not give me a horizontal error at different differences. Unfortunately the BKL was moving on my rail because of the lack of a stop pin.

“Then I decided to buy a good one-piece mount with a stop pin. But before that I checked my other Chinese one-piece mount. I mounted the BKL and that mount on the same rail and then I put a small BB at the bottom of each mount ring. I noticed that the BB on Chinese mount was displaced, relative to the BKL’s BB. Then I turned around the Chinese mount and did the same test. The BB was then displaced to the opposite side, so it means that the mount is not aligned with the axis of the rail. Actually it was near 2 mm of displacement. If the mount is for 9-11 mm rail it’s probably good for only a 9 mm rail.

“So here is my question. Will the Sportsmatch mount be axial to the rail, because I’m afraid it won’t? What should I do? Is that really important to have axial mounts on your airgun? Should I use a file and extend the not moving jaw of the mount to make it more axial?

“I was searching for your posts about that issue but I didn’t find any. If there is one, please send me how is that called or link to that post.

“I will be grateful for any reply. Thanks in advance for your time.

Best regards,
Matt”

What a question! Matt knows what many airgunners have discovered — scopes don’t look at exactly the same place that the bores of their rifles do. As you shoot close or far away, the pellet will move from left to right or vice-versa. I have written about this several times in the past but today I’m addressing it again. Matt, I never used the term axial, so that may be why you didn’t get any hits.

The bad news

Matt, the bad news is that no rifle on this planet does what you ask. I will get into the reasons for this in a moment, but don’t take it too hard. You asked if this is that important and the answer is no, it’s not. You can work around it and get what you want, despite it being virtually impossible to align a scope optical axis with the bore of a rifle.

Details

Here are most of the many reasons why scopes and rifle bores are never precisely aligned.

The barrel

We will start with the barrel. It is virtually impossible to drill a hole and rifle a barrel so that the bore is parallel to the outside of the barrel. But no matter because it’s not important. However, there are some anal benchrest shooters who think that it is important and they have their barrels machined outside to be parallel with the bore. This costs a lot of money (hundreds of dollars) and does absolutely nothing for accuracy. Know why? Because the place where the barrel joins the action of the gun determines where the bore “looks,” not the outside of the barrel. The center of the bore can be offset a quarter-inch from the center of the barrel and make zero difference in where the gun shoots.

Now, the place where the barrel is joined to the action does matter. That is what determines where the bore “looks,” relative to the action. So, time invested in getting that right is time well spent. But there is a fly in the ointment of today’s question. What kind of air rifle is Matt trying to scope? A Weihrauch 50 — HW 50. That’s a breakbarrel rifle, and we know that every time that rifle is cocked the barrel (and therefore the bore) moves, relative to the action of the gun.

breakbarrel
When a breakbarrel rifle is cocked, the axis of the bore and scope diverge.

However, this movement doesn’t matter as long as the barrel returns to the same place every time. And it does. So we can ignore the fact that the bore moves. Let’s move on to the gun.

Is the scope base parallel to the axis of the bore?

The answer to this question is no — most of the time the scope base (11mm dovetail grooves cut into the spring tube in the case of the HW50) is not parallel to the axis of the bore. I can illustrate this with a term we all know — barrel droop. Those who shoot breakbarrel air rifles know that most of their barrels point downward, away from the axis of their scopes. It’s the reason that droop-compensating scope mounts are so popular today.

drooping barrel
This rifle has a droop that’s extremely large, but it illustrates the point I’m making.

What about side-to-side?

I have only talked about the relationship of the scope and bore up and down. What about side-to-side? That can be off, as well, though it’s not commonly as big a problem. But some airguns have scope bases that are attached to the top of the spring tube, and those bases can be attached incorrectly, so that side-to-side becomes a problem. The fix for this is not the same as for up and down, because the trajectory of the pellet doesn’t come into play. In short, on a side-to-side problem gravity isn’t an issue. But it still needs to be corrected.

Scope mounts

Now that we understand the problems the gun presents, we still must consider the scope mounts. If the holes through the rings aren’t aligned with the ring bases everything else can be good and we still won’t get the scope and barrel to look in the same direction. The solution here is to use quality rings. And two-piece rings give you options for alignment refinement because you can turn them around or swap them on the rifle (front and rear). You can even swap them and turn them around individually, which gives an even greater range of adjustability. Matt mentioned doing this, so he understands the finer details of scope mounting. But now I want to stop talking about hypotheticals and get down to the answer.

The answer

Matt — let’s go back to those BKL 263 scope rings you say were slipping on your HW50. I have never heard of any BKL rings that are properly installed moving on any spring rifle, let alone one that is as smooth as the HW50. Something must be wrong with your installation. This is the very ring I would have recommended for the HW50 because of its precision. Are the rings really moving, or are you just concerned that they might? Because they won’t. Unless the rings are improperly installed or damaged in some way, they will hold onto the scope base of an HW50 so tight that any scope can be mounted securely.

Greater precision?

If you want the absolute last word in precision scope rings take a look at the UTG P.O.I. rings. I showed them in detail in the report titled Optics test. I doubt there are rings on the market that are machined more precisely than these.

However…

But here comes the real answer. Chasing specs like this to align a scope with a bore is a futile drill. Several years ago you read a lot about people finding the optical center of their scopes. There were even different techniques for doing it being widely discussed. You don’t read much about it these days because most shooters have discovered that it doesn’t make any difference. I remember 20 years ago when world-class field target competitor, Ray Apelles, told me that he had abandoned finding the optical center of his scopes. Instead, he just kept mounting and remounting his scopes and testing them after each tweak — by shooting them at different distances on the range and noting any shift in impact, side-to-side.

Ray told me that after he had optically centered a scope, none of his rifles would then shoot that scope correctly without some tweaking — FOR ALL THE REASONS MENTIONED AT THE BEGINNING OF THIS REPORT. It turns out that trying to fix the problem with specifications is a waste of time and money, because in the end all rifles have to be tweaked before their scopes and barrels can be correctly aligned.

Close enough

Hunters get away with not doing this because the error rate (the amount the scope or bore is off the target) is usually very small. A bird doesn’t care if your pellet hits him a quarter-inch from the point of aim. A field target, on the other hand, can lock up and not fall if the miss is that great. You lose points. So those folks who really have to hit exactly where they aim find it worth their time to do the work of tweaking their scopes and mounts — at least the winners do.

What is meant by tweaking?

To tweak a scope or mount, you use all the tricks in the book — shims, adjustable scope mounts, two-piece rings that can be swapped, front and rear, and also turned around. Matt mentioned that his Chinese scope rings were off by 2 millimeters. Ray Apelles had mounts that varied by as little as the thickness of the vertical crosshair, depending on the way they were turned. That’s how a scope is tweaked.

And don’t forget to install a level on your rifle. That way you shoot every time with the crosshairs and bore in the same attitude. Three degrees off at 45 meters will drop your pellet by half an inch if your gun shoots at 850 f.p.s.

Never perfect

And — get ready for it — even with all that you do it never works out perfectly! Hans Apelles, Ray’s father, told me they could get their rifles hitting where their scopes indicated to within half a pellet diameter at 50 meters, but they had to account for that final bit with holdoff. That’s correct — men who have placed in the top ten in world competitions and click-adjust their scopes for every shot would also hold off by the tiniest margin, depending on the range and the target.

Summary

So, Matt, you can go one of two ways, but not both. You can either chase after rings that are perfectly aligned with the bore of your rifle when they are installed on the scope base of that rifle — which I said can never happen — or you can spend the time it takes to modify and fine-tune (tweak) your scope’s alignment until you have gotten it as close as possible. You may even need to try many different sets of rings until you find the set that works the best. Scope mounting like this doesn’t take minutes, it takes weeks. But it’s the only way to get the job done right.