Scope Zeroing Problem

[ejr010]

I have a Shadow 1000 with a new BSA 3-12x44AO scope and Leapers Accushot high mounts.  I mounted the scope today and zeroed it in.  Scope is great and accuracy seems very good so far.  But, I had to turn the windage adjustment knob all the way in to get dead on to the target.  So I have no adjustment left.  Any recommendations on how to adjust the scope mounting to bring the adjustment closer to center?  I have followed good torque procedures for tightening the mounting screws and the mounts appear to be tight and installed properly.  I did not over tighten the scope tube clamps.  Any ideas?

Jack

[Gil]

Try putting film negatives on the rear mount (nearest to the stock). That is the only method im aware of, but maybe others will share some info.

[longislandhunter]

Just curious,,,, did you inspect the dovetail grooves in the receiver? Are they postioned correctly,,,,, are they centered on the receiver top and in line with the axis of the barrel? Also,,, are you sure the scope is sitting properly in the mount???

Jeff

[Big_Bill]

Hey Jack,

Check your scope mount, you may have one of the clamps upside down, causing it to pull hard toone side.

If not, check to see if you have a bent barrel, put a straight edge along the barrel on all sides.

Bill

[ejr010]

All, thanks for you help.

Bill, I may have both clamps on upside down - I'm not sure which way they go.  I have them both installed with the longer leg in the receiver dovetail.  The shorter leg is in the mounting hardware.  Is this upside down?

Gil, if the clamps are not the problem, I'll try using the film negatives (if I can find any in my old photo storage box).

Jeff, everything you mentioned seems to be in good order.  Also, I did not have any problem with the adjustments on my old BSA 9x32 scope.

Jack

[Big_Bill]

Welcome to the GTA Forums Jack,

I didn't notice that this was your first post ! It's good to have you here, a member of our airgun family.

Now, did you have you BSA scope on the same mount ? or did you have different mounts ?

And you did say windage adjustment, correct ? That is right and left

Bill

[ejr010]

Big Bill, this is my first post.  I've been reading the posts for several months and have learned much about air guns.  What a great source of information on air guns.

I bought new Accushot high mounts for the new BSA 3-12x44AO scope.  The original BSA 9x32 scope had low mounts which were not suitable for the new scope.  So, new scope & new mounts.  It is the windage adjustment that is screwed in all the way so that I have no more windage adjustment to the left.  I was able to get the scope adjusted to dead on target, but I ran out of adjustment getting there.

Jack

[Big_Bill]

O.K. Jack,

I guess you'll just have to remove the mounts and check the rails to make sure that there is nothing clogging them. The Accushot Mount has reversible locking clamps, and the other side may fit your scope rails better, and correct your problem.

Jeff (longislandhunter), has the best procedure for mounting scopes and rails, that I have ever heard of, Clean your rifle scope rails, your scope mount, screws, rings and ring screws with alcohol, don't drink too much of the alcohol !, reassemble using blue lock tite (non permanent blue), on all screws, and rails, let dry for 24 hours. Do this only after we find your problem !!!!!

Bill

[ejr010]

Bill, thanks for your help.  I'll try reversing the clamps and see if that helps.  I'll also check the rails and mounts for clogging and follow Jeff's procedure for scope mounting.  I'll report back later with results.  Thanks again.

Jack

[ejr010]

Last night I removed the scope and reversed the mounting clamps as recommended.  I removed all the fasteners and inspected all the parts for anything usual - but found nothing that seemed to be a problem.  Most difficult part was cleaning the Loctite Blue #242 from the fastener threads.  Went outside this afternoon to shoot and see if this solved the problem.  Well, it did solve the problem - but I don't really understand why.  I now have plenty of windage adjustment.  Originally the clamps were slightly canted outward at the receiver dovetails and after reversing the clamps were slightly canted inward at the dovetails.  I plan to fire a few more rounds and then disassemble again and use the Loctite Blue the threads.  Bill, thanks much for your help - I would have never suspected the clamps and I didn't know that they were reversible.  I'm new to posting but I will try to attach a few pics of my gun / scope / clamps.

Jack

Jack, I think that's by design of the Accushot people, as well as other scope mount manufacturers probably. The side clamp piece is deliberately made to be used right-side-up or upside-down depending on if the grooves in the scope mount are spaced 11mm or 3/8" apart (I think that's the right dimensions-- somebody throw me a line if that's wrong). If both of the pieces are flipped one way, they'll fit one groove spacing and if they're flipped the other way, they'll fit the other size. The Accushot one-piece mounts are the same way, I think, with the single side piece. The design necessitates slightly different dimensions on the dovetail mating surfaces (maybe even different angles for the "points"), so even though they "fit" on your grooves, they were backwards. Sounds like you've gottem headin' in the right direction and ready to go.

Hope that helps.

Bryan

[ejr010]

Bryan, it does make sense that the clamps are made to fit the two different size dovetails.  I just wish the Accushot mounting instructions would have mentioned something about the reversible mounts.  There was no mention at all in the installation instructions furnished with the mounts.  Anyway, I'm happy to have the scope properly mounted now.

Jack

Jack, now that you mention it, I guess I'd always just assumed that the Accushot mounts had their little plates oriented correctly from the git-go, and didn't even think that there MIGHT be an alternative plate position until mounting a one-piece set on one of my shooters (can't remember which one at the moment) and seeing that the whole mount looked cock-eyed even before putting the scope on. It hit me that the plate was asymmetrical, and decided to try it the other way. I don't think it ever occurred to me to see if there were any instructions on that folded up piece of paper included with the mounts ("It's just scope mounts-- how complicated can it be, Bryan-stein?!?"-- LOL!!). At least you knew enough to have LOOKED at the instructions ;~D Sometimes I'm amazed that I routinely survive my blissful ignorance heh, heh.

Bryan