I have two Leupold scopes that have the disconcerting tendency to give a little jump or wiggle to the reticle when I dry fire the bolt action rifles that they are mounted on.

Both seem to hold accuracy well enough, although I am beginning to wonder if the rifles would be more accurate if this wasn't occurring. This "jiggle" doesn't seem to happen in any of a dozen other rifles that I shoot.

Mounts are tight, bedding is good, action screws tight, so I believe it is some kind of play in the internals of the scope. So what would cause this? Weak springs in the adjustment/erector assembly?

Your theories and experience welcome.

I doubt seriously that it is the scope, I posted a similar question a bit ago and got some good input. If there was "wiggle" it would most likely not be holding accuracy.

I agree, if you are getting wiggle from just dry firing, you WILL NOT get good accuracy. Nuff said..

I don't know the precise answer to this but I have seen it myself...and actually with some rifles that shoot rather well.

I have heard that in some instances it's related to the way the locking lugs engage their recesses,and the bolt,and lugs, can actually be tilted when under tension while the rifle is cocked under tension.

When the trigger is pulled, then the tension is released,and the lugs slam into alignment,causing those weird vibrations to make the reticle "jump". probably happens with rifles whose lugs have not been properly mated to the locking luck recesses.

I could be all wet on this and am happy to see some skilled accuracy smiths who know their way around this stuff to chime in. Maybe Butch lambert or Redneck know the answers to this.

In any case I don't think it's the scope.

For me, and I used to be a fairly decent shot, there is always wiggle with optics dry firing, even off bags on the bench. I"ve never been able to make it stop completely. But it becomes very very minor when you practice. One reason I tend to dry fire a fair amount, even when out in the field to stay sharp.

That said, if you see more in the 2 guns, than in the others there is an issue of something, BUT if the accuracy is there....

First I"d swap scopes out and see if it follows the gun or the scope....

You always have body movement and muscle tension, thats a given, laser training will show what the eye can't even see at times.

But if it follows the gun or the scope once you've swapped, but if the accuracy was good enough, I"d not sweat it personally.

If it followed the scope, obviously I"d send that in to see what the factory could do. But if its the gun, I don't know there is much you can or need to do. A gunsmith might be able to answer the gun question better.

Moves a tad or wiggles? Trigger pulled, sear lets go, firing pin spring slams forward and stops, bolt handle on most raises some and vibrations are sent thru the rifle. Unless you have the rifle in a firm grip you see a little reticle movement. If it continues to move, i.e. wiggle, there is a problem.

Is your ocular locked down tight and not moving?

The firing pin is moving the rifle as it slams forward. I bet if you put a dial indicator on the turret caps, you'll see the scope is actually moving in the x and y directions. If you lock the rifle in a solid rest or a vise, you should see a large reduction as the force is absorbed by the larger mass. A bunch of sand bags or lead shot would be best.

Also, I've noticed on rifles that he bolt isn't perfectly timed (handle jumps when dry fired) the illusion is more pronounced of the reticle jumping.

Yup. Good explanation.

I bet the rifle has a heavy firing pin to boot

There is another explanation: The erector tube inside all riflescopes moves under recoil because it is not fixed inside the scope, if it were fixed you wouldn't be able to adjust your zero. It is held in place against the turret feet with spring tension. It is possible that the inertia of your firing mechanism is enough to override this spring tension resulting in movement of the image in front of the reticle (or apparent reticle movement). The same thing happens with recoil, you just can't see it.

Thanks for all the thoughtful replies everyone. I have a little experimenting and observing to do now, part of the learning process. I'll try to let you know soon what I observed.