The ed­i­tor is in a scope swap­ping frenzy on the test range

Air Gunner - - Contents -

Phill Price weighs up the pros and cons of swap­ping scopes

Over the last decade, the Weaver stan­dard scope-mount­ing sys­tem has slowly been creep­ing into the airgun scene. As much as I un­der­stand why you might use it on a .50 cal, heavy ma­chine gun, I don’t see why you’d want it on a re­coil­less airgun. The 11mm dove­tail has served us per­fectly for many decades and is sub­tle and dis­creet along the back of our beloved ri­fles. This is how I feel sport­ing guns should look. Weaver rails look far too mil­i­tary for my eyes.

No scope shift

Hav­ing a steel bar that runs at 90° across the rail en­sures that no amount of re­coil can shift the scope, but that’s of no rel­e­vance to air­gun­ners us­ing re­coil­less pre­ci­sion air­guns. What it could po­ten­tially do is of­fer an ‘ in­dex po­si­tion’, so that as you change from one scope to an­other you could po­si­tion it fore and aft against a fixed, hard­point, for the sake of con­sis­tency.

The only sen­si­ble ex­pla­na­tion I’ve been of­fered for its us­age, apart from look­ing ‘ tac­ti­cal’, what­ever that means, is that you can have a num­ber of sights ze­roed for your

ri­fle and can swap them over in­stantly. Of course, each one needs to go back to the pre­cise zero or it’s a worth­less ex­er­cise. If you have to shoot a pa­per tar­get to be sure, and make a small amount of ad­just­ments, you might just as well stick with the ubiq­ui­tous 11mm stan­dard with a hard stop­point on the rail.


To un­der­stand if this re­turn to zero claim was fact or fiction, I sourced an 11mm to Weaver adap­tor rail made by B-Square and got two scopes that I know and trust, set­ting each up in Weaver rings. I chose to use my BSA R10 MkII be­cause it’s stun­ningly ac­cu­rate and its mag­a­zine sits low in the ac­tion, so that there’s no cut- out in its rail. Next, I ze­roed each scope care­fully at 35 yards, on a rel­a­tively calm day so that the wind wouldn’t be too much of a fac­tor, al­low­ing for the fact it al­ways is to some de­gree.

Be­cause the scope rings are tight­ened with thumb wheels, I be­lieved that the torque of the fit­ting bolts wouldn’t vary too much and af­fect the re­sults. I’d just do them up as tightly as I could with my fin­gers, which shouldn’t give too much vari­a­tion.

My plan was to shoot a group with scope A, re­move it, and fit scope B, then shoot an­other group. I’d re­peat this un­til I had enough groups to form an opin­ion of the re­peata­bil­ity of the zero. Would scope A go back to zero ev­ery time? Would scopes A and B be dead on, or miles off? What was needed was trig­ger time and a good deal of pa­tience.

As the pic­tures show all too clearly, the scopes did go back close to zero ev­ery time. I find this kind of test re­ally tricky to trust com­pletely be­cause we never shoot per­fectly, and out­door con­di­tions are al­ways a fac­tor even in rel­a­tively light winds. I’d get all stressed when a shot went wide and then ex­cited when I got a clover leaf group on the bull. The re­al­ity is that there are lots of vari­ables be­yond the mount­ing sys­tem in ques­tion.

Easy swaps

The prac­ti­cal re­al­i­ties were that I found swap­ping scopes some 60 times no big deal, although it was clear that one set of mounts fit­ted the rail dif­fer­ently to the other and took many more turns of the thumb­wheels to tighten fully. If I were to run this test again, I’d swap the thumb­wheels for nuts and tighten them with a low-range torque wrench to elim­i­nate that vari­able.

The bot­tom line is this. No shot landed more than ½” away from the bull dur­ing the re­moval and re­fit­ting of the two scopes. Is a 1” group good enough for you at 35 yards? Some will say yes, oth­ers will say no. The mounts were top- class units from Sports­match and the base from B-Square, both pres­ti­gious com­pa­nies, so no cor­ners were cut to save money.

Can I now say that two scopes in Weaver mounts can be re­moved and fit­ted with NO change of zero? That’s too hard to say, but I did prove that they come pretty close and for those who swap from day to night vi­sion, they’re an hon­est op­tion. How­ever, be­ing an ac­cu­racy nut, I like to set­tle a gun down by break­ing it in slowly, get­ting the op­ti­mum zero, then lock­ing the whole thing down and leav­ing it alone. I like to know that my ri­fles are dead on as they leave the gun cab­i­net, and any­thing I can do to as­sure that is what I’m go­ing to do. I’ll be stay­ing locked to 11mm rails for the fore­see­able fu­ture, but then you knew that about me any­way.

Trig­ger- time is the only way to an­swer some ques­tions Would the scope go back to the ex­act same place ev­ery time? I did the bolts up fin­ger tight for this test No amount of re­moval and re­fit­ting seemed to af­fect the zero sig­nif­i­cantly

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.