WHY am I tapping on my scope?

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danbnimble

Guest
I hate to even ask....Has it always been that one should tap on the windage and elevation adjustments to make sure the cross hairs move? Middle of the road scope, Nikon Monarch series. Does this need to be done with high end scopes also? Can't harly think so. Or...is there a fix?
Nice day thought I'd go to the range
 
Dan,
Monkey see monkey do ? That's about all I can figure. From the scopes I have seen torn apart the turret screws move predictably,they push a little ball bearing that in turn pushes on the erector tube that is held by a friction fit ball joint in the erector tube housing( I'm hoping Jackie will correct my misconceptions and lack of nomenclature)That is where the hang-ups and snags occur,not in the turret itself. I think maybe smacking the entire scope( after turret adjustment) with a wet hand towel might be a better approach,or you can just do what most guys do and shoot the gun three or four times so the adjustments can settle.
Joel
 
i may be way off base but

every one of us that has worked with bolts and screws has encounteered a screw that just about destroyed the screwdriver bit to get it started to loosen. then when we asked an experienced mechanic they told us to give the screw driver a whack on the end with a rawhide mallet before trying to back the screw out. then it turned out so easy. it all has something to do with how the threads fit each other, corrosion, dirt and other stuff that life works in there.
using that theorum when one makes the adjustment it is to settle all the differing parts (threads, reticle tube, spring, and transfer ball on end of adjustment screw) before making the next sighter shot. just like one other poster stated if one shot the rifle it would settle everything. well yes, but who wants to waste that much ammo when a tap with the coin one used to move the scope adjustment will do. actually one probably dont have to do this but if you just ranged that woodchuck in and need 3 clicks to get spot on, it will haunt you for the rest of the day if you miss. keep saying i knew i should have tapped the elevation turret to harvest that chuck, dang it!!

chuckling, Fred
 
Nader,

What brands were the scopes that you disassembled? I am under the impression that Weavers are the only ones that have transfer balls, by all accounts, an excellent feature. Of course you have me at the extreme disadvantage of having taken a modern scope apart. I seem to lack the courage, or perhaps it is self knowledge.
 
Dan

Scopes are a mechanicle device. As with any mechanicle device, especially where moving parts are concerned, there are clearances that are involved that must be present to allow the pieces that have to move, be moved.

Keep in mind, the only thing that holds the erector tube against the turret abutments is a spring, or springs. Regardless of the precision involved with the parts, logic would dictate that the final, and firm, seating of the mating parts might not finally reach their final position untill subjected to an outside force, whether it be tapping the scope, or firing the Rifle..........jackie
 
thanks guys

the question that originated visually in my head was...does the spotter for a sniper check with his shooter to make sure he tapped the turrets just before he tells him to send one. I would be willing to believe not, but I could be wrong.
The world I live in says (for the most part) you get what ya pay for....so am I to assume a $1800.00 Nightforce has the same issues? Or no...
 
I have been playing with a scope testing devise for a few weeks now. It
has evolved and improvements have been made. It mounts two
scopes side by side much like a hood scope checker, but does not
mount on a gun. The whole thing is over 50 lbs and cannot be canted
as the hood scope checker can. It uses a frozen weaver with glass
reticle and the objective is also frozen. It is not with out drawbacks,
as the objective is out of focus when the temp changes.
Nearly every scope I have tried, responds better to positive
motion in the turrets better than negative. That the springs alone
doesn't fully seat the erector tube seems real.
 
Bob,

Just to clarify, you're saying that they react better when you screw the adjustments in towards the spring, not out away from it, right?

The next step is, does that mean that elevating the sights is gooder & likewise right wind, or am I base over apex with what goes on in a scope?

Thanks

John
 
Tester

Bob Kingsbury said:
I have been playing with a scope testing devise for a few weeks now. It
has evolved and improvements have been made. It mounts two
scopes side by side much like a hood scope checker, but does not
mount on a gun. The whole thing is over 50 lbs and cannot be canted
as the hood scope checker can. It uses a frozen weaver with glass
reticle and the objective is also frozen. It is not with out drawbacks,
as the objective is out of focus when the temp changes.
Nearly every scope I have tried, responds better to positive
motion in the turrets better than negative. That the springs alone
doesn't fully seat the erector tube seems real.
Click to expand...

Bob, I also made a dual scope block a few weeks ago, but mine is a lot smaller than your 50#. I set two scopes for the same point and pick up the unit and tap it in several directions to look for changes. I've not seen an immediate change, but it seems that if the unit sits a few days the points will somehow drift maybe 1/4-3/8". At present, I have a weaver t36 and a tasco 10-40 side by side. I tend to leave the weaver alone and do all my adjusting on the tasco. The tasco is actually not bad. If you move one click in either dir., the crosshairs move the right amount. One click back and you are at the exact starting point again. I've still got a lot of testing to do, but at least now I have confidence in both of the scopes I tested.
 
Years ago, the late Dick Thomas of Premier Reticles told me that one should always finish a turret adjustment turning the turret in, and that this is for the reason that Bob mentioned. You cannot depend on the spring, or springs, to make the erector tube stay in full contact with the end of the turret screw. For that reason, when I make an adjustment that has the turrets being turned out, I usually go 1 MOA past and come back in to the setting that I want. Even so, since I usually have cleaned at a yardage change, I shoot 2-3 shots at one of the side sighter aiming points to establish that things have settled in, and given that I have had a few surprises, under those conditions, it probably should be 3-4, but I think that this is mostly about reestablishing a uniform bore condition, in some barrels.

Bob, I would like to see a picture of your checker some time. Also, you said that you froze the objective in your reference scope. Have you any sense as to how much reticle movement might come from objective cell movement? Have you seen what Jackie did to one of his 36X Leupolds to address this issue?
 
I cannot say how much movement can be credited to the front end of my
frozen weaver. After freezing that, however, the failure rate was reduced
when the same scopes were tested. Of 8 scopes tested, actually 9 now.
the ones that move, do not always move exactly the same amount. My
notes say the errors do repeat in direction. One scope seems to have a tilted
front lens, as the crosshairs can be made to prescribe a circle when it is
changed. Much of this is lost as it is then out of focus, but by sittiing back
and looking thru the black and much narrowed field it can be seen.
Boyd: yes, I have seen a picture of the objective modification on
Jackies scope, however I know nothing about it. When I'm satisfied
that I'm actually getting somewhere, I will post a picture of this
hard to lug to the bench monster.
 
Bob-Boyd-Jackie et al- I learn something here just about everyday. When you are referring to "In" and "Out" I'm assuming that's up/down or left/right? Which is in- up or down, left or right?

What are you tapping on the scope with and where (Tube, turrets)? Thanx.

Cheers,

Mark
 
Turning either turret counter clockwise would unload the tension
on the springs . This would be turning to impact rt or up.
I cannot say that tapping scopes is required, only that they
seem to respond better one way than the other. As Jackie said,
if its adjustable , it no doub't has backlash. My concern is, do
the scopes move in a group
 
Thanx Bob. Okay, I now see I should have referred to "Clockwise-counter clockwise" vice up/down left/right.

Cheers,

Mark
 
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