Recently I came into possession of a BSA 'Catseye" 4-16x40 scope that came attached to a rifle I was buying, a Savage 25T in .223 Winchester.

The scope gave me fits.

Even though it had 1/4" clicks at 100 yards, I could get it to shoot either 1/2" to the left of the bull, or 1/2" to the right - but not on the bull itself. I did get good groups, though.

Then I took the gun home and cleaned it... When I returned to the range, the elevation was OK, but now it was shooting 3" to the opposite side of the bull from where it had been!

Scope mounts and rings checked out OK... I got to thinking, waving away the wood smoke that this generated and finally thought about tapping the scope next to the adjustment barrels with the butt of a plastic-handled screwdriver.

Next time out, I would give the scope a few good taps with the butt of the screwdriver handle after every adjustment, and it started behaving itself. Now it shoots directly into the center of the bullseye, and stays put between shooting sessions.

It just needed a little judicious, gentle tapping to start working well enough to get me by for the time being. It gets all of the internal parts settled into place so that it holds its adjustments.

I thought I'd mention this technique in case somebody has a misbehaving scope that they can't replace right away.

Love the story. Interesting that you spent the time to get it right. Course if you just bought a $1000 scope like most members suggest then you probably would not have learned anything like doing it yourself. Only be out $1000. Most members will be shocked that you found it worthwhile.

Back years ago, tapping your scope while sighting it in was common practice.
Optics have come along way but I still do it out of habit.

So do I, even on the expensive scopes.

So do I.

Except on scopes that are supposed to track.. I don't tap on that one.

I've been in that habit for years, I even tap my Aimpoins and Eotechs, a lot of time it's with the ground when going from standing to prone. They hold their zero perfectly so it must help

We have a mess of old leupolds. If you adjust it to go say 4 inches to the right and don't tap on it, your first shot after the adj. it wont change point of impact second shot it will move a little and then in a few more shots it will move the rest of the way. Once zeroed ive had great luck with them, but you cant "dial" for elevation like some scopes.

tapping your optic to settle the internalshas always been step one after i adjust it

hmm.... never heard this....

First I ever heard of this was Peter Capstick talking about sighting in a .375 H&H for a client to take a leopard with. Read that book in the early 80s.

I do it on older scopes if adjusting out away (counter clockwise)from its previous position. Older reticles seem to stick sometimes. Not sure if they have some type of grease or if whatever spring mechanism holds tension on the reticle gets a little memory.
My old 4x Redfields are the worst.

I still do that out of habit, usually with the base of the shell I just fired.

My wife's birthday is coming up soon, and she probably would not understand if I bought her a new scope for my rifle... Women are strange that way, but you've still got to love them.

On account of that, I'll have to wait for a couple of weeks before I can replace the BSA with something a little nicer. It will get me by until then, and then I guess my son and I will have fun taking it apart. - I wouldn't foist the thing off on some unsuspecting shooter.

Now I think I'm seeing why I got a good deal on the rifle... The previous owner probably blamed the gun when it was really just the scope having problems. The rifle shoots bug-holes, there's nothing wrong with it.

The new scope will have to wait though... She's wanting perfume, so I've been looking at the big bottles of Hoppes #9.

Been doing that same thing for years.