"Sticky" scope adjustments

M

Montana Pete

Guest
I happened to read an old copy of American Hunter and read a scope review. The review showed a problem that's also true of my own scope.

Has to do with "sticky" scope adjustments. I call them that-- don't know it its the best description or not. Here's how it works -- You remove the cap on your scope turret and turn the adjustment dial. Suppose you are trying to move the center of impact three inches to the right. That's twelve clicks at 1/4 inch per click. You do that -- Next you start to shoot and your group shows an extreme horizontal spread. It takes several shots -- walking the holes to the right -- until you obtain your desired change. Seems like it requires the recoil of shooting to "seat" the adjustment. It may take several shots to entirely make the shift.

The American Hunter reviewer liked everything else about the scope being reviewed. But he was irritated by these "sticky" adjustments. He discovered that if he rapped the adjustment turret real smartly, like with a hunk of firewood, he could get the changes to "take" a lot more readily.

This scope being reviewed was NOT the scope I have. Is this fairly common? So this shows that at least two brands of scope have this problem. Has anyone else discovered this problem?

Before I shoot for record, I usually shoot 3 to 5 fouling shots. Now, aware of this scope situation, I make my adjustment with a cold gun, right out of the car. The fouling shots usually settle the scope down, leaving me a stable scope for my record shots.

Unfortunately, if I see the need for more tweaking of the adjustments, I have to put it off until my next trip to the range. Otherwise I will ruin my record groups.

My scope is a Bushnell Trophy 6-18X variable. Except for this "quirk" I like it fine. I seem to be getting exc. accuracy out of the scope/rifle combo.

Any comments are welcome--
 
When discussing this topic with the late Dick Thomas of Premier Reticles, he told me that when making an adjustment that involved an unscrewing motion of the turret (usually up or right) that one should go past the desired setting and then come back to the desired setting. This is because when you unscrew a turret, you are depending on the leaf spring to make the erector tube follow the retreating turret contact surface. By going past ( when unscrewing) and then to your desired setting you may avoid this problem. I have also found that "exercising" turrets can be beneficial, that is running them to their extremes and then back to the desired setting. Doing this every so often may help the reliability or their action. As for tapping, a plastic screwdriver handle, carefully applied, has worked for some. I try to avoid banging on scopes, although I have seen some (none of mine) that it could only improve.
 
Interesting. I always adjust by going past then coming back to where I want. If I want to move 2 clicks, I go 4 and back 2. Now I know why it works! Thanks and happy Thanksgiving. bob finger
 
You too Bob..
Just remember to go past only when the adjustment is in a counter clockwise directrion. When adjusting in a clockwise direction, just do the adjustment without going past.
Boyd
 
Just To Add

I have had several brands of svopes apart, they all, more or less, work the same way. You have an erector tube that is held secure on one end by some sort of gimble ball joint, and the other end is held against the turret abutments by a spring.

Since the turrets, and the gimble ball joint, all have to have a certain amount of clearance in order to move, they will have a certain amount of slack and backlash. This is a simple fact of a piece of mechanicle equipment.

The light tapping can aid in assuring that everything finally seats, (keep in mind, the only thing causing this to happen is spring pressure), abd taking the slack out as suggested is certainly a good idea. But even the best scopes can often take a shot or two to finally settle in........jackie
 
scope slop?

Yes, I have had those experiences with scopes that range in price from $250-$825. And in case anyone is wondering, I don't tighten my scope rings "farmer tight". Stan-share your sport:)-Happy Thanksgiving!
 
You must log in or register to reply here.
Back
Top