B-Square adjustable scope mounts - Part 3
by B.B. Pelletier
Today we will adjust the B-Square adjustable mounts for windage. You may have noticed yesterday that the setscrews that lock the windage adjustment screws are on one side of the scope ring. When you turn the rings to adjust for elevation, these setscrews will either wind up facing out (to the back or front of the scope mount) or in (toward the other scope ring). With some scopes, that can present a problem for accessibility for the Allen wrench, so give it some thought before you decide on a setting. And extra half-turn in the rear usually doesn't upset things too much, but just remember to leave some space UNDER the rings at the front.
This is the 10-40X56 Tasco Custom Shop scope I used for years in field target. It was mounted on my Harrier. The front ring on the left has 1/2 turn of elevation, and the rear ring has one turn. Because the Harrier is a PCP, it didn't need much correction.
The adjustment screws work by pushing against the split ring that is screwed to the stud. Tightening an adjustment screw pushes the stud and split ring AWAY from that side of the scope ring, which pushes the scope ring TOWARDS the screw you are tightening. This is confusing until you think it through, so I will provide a table of adjustments.
Always loosen the adjustment screws first. Right and left refer to the sides of the rings when you are holding the gun as the shooter.
To move the pellet strike to the right, loosen the left adjustment screw and tighten the right screw. To move the strike of the pellet to the left, loosen the right adjustment screw and tighten the left.
To move the strike of the pellet to the right, loosen the right adjustment screw and tighten the left. To move the strike of the pellet to the left, loosen the left adjustment screw and tighten the right.
Remember - BOTH rings adjust
Sometimes you will run out of adjustment on the rear ring. Just use the front ring to go farther. I have never seen an airgun so far out of whack that it could not be adjusted with these rings.
The object is to adjust the scope using the rings and leaving the scope's adjustments alone. If you centered the scope's adjustments before starting the mounting procedure, you will have the entire range of scope adjustment available after the rings have been properly adjusted.
You don't always need adjustable rings!
If a three-part blog hasn't convinced you, please believe me when I say that the mounting and adjustment process for B-Square adjustable rings/mounts is very cumbersome. But it isn't always necessary to use them. Try to get by with non-adjustable mounts/rings if at all possible. However, when you are faced with a real scope mounting challenge - these are the rings to buy.
To snug your scope mount down, the windage adjustment screws must be tight. Remember that as you do tighten them, you may be moving the zero you have set, so try not to do that. I find it easiest to snug down one ring and then make the final small adjustments on the other ring as I am snugging it down. After both adjustment screws are tight, tighten the setscrews and the job is finished. If your scope is still not tight, you have probably gotten the noses of the adjustment screws out of the holes in the split ring. They must be in those holes for the ring to be secure.
Reader Paul Capello reminded me of this important lesson. The mounts are made of aluminum and the setscrews are steel, so the screws will strip their threads rather easily. You don't need to torque any of the screws that tight to have a rigid mount. Here is Paul to tell you in his own words.
I've found that with the B-Square 17101, by removing the top half of both scope rings and using a lighted magnifying desk lamp, I can easily align the dimples on the split rings with the points on the grub (set) screws. This also helps me approximate and center the bottom half of the scope ring. Once you get all the parts "floating" properly, it takes very little torque to clamp down the rings.
Once set up correctly, there has been 0% movement on my RWS Mod 34 after hundreds of shots. I do admit that I rushed setting up the first 17101 that I purchased, but B-Square was happy to replace the parts I stripped with no questions asked.
I did also clean the parts carefully with denatured alcohol right out of the package. This helped tremendously. This is a great product for droopers!
If you plan on using B-Square adjustables, I would bookmark this posting, which contains an index to all the others.