I noticed something with a few scopes a few years a back and have never found an answer. I was shooting a few of my most accurate rifles, things were dialed in well and groups were sub 1/2 moa.

The scopes had a pretty short eyebox on high power so I decide to try to move them back a bit in the rings. I loosened the rings and just slide them back a little, less than an inch. Tightened them back up and went back to shooting. My accuracy went to crap. Two in one out random type crap like the retical wasn't staying in the same spot, maybe binding a little. Slid the scopes back to were they were and accuracy came back.

I had a similar experience the other day when I moved a scope back in the rings to try to get the brass to clear my windage turret better on a stiller action with m16 style extractor that throws brass a little high like they do. Accuracy went to crap and returned wen I moved them back.

Im thinking that were the ring is clamping down on the tube body can effect the internals different depending on were its clamping down at. What are some good general rules about where to have the rings on the tube and where not too.

I know someone here once said something about screwing up a Leupold 6x42 by mounting the rings in the wrong place.

Educate me, I feel like I missing something. Sometimes I think a lot of scopes partially go out and go to 2 moa shooters without totally being trashed. I can be frustrating because hi think it's just a bad load or something else and then switch scopes and everything comes back. If a scopes going to go I prefer it to really go, this slightly eradict stuff can drive you nuts.

I've noticed lately another thing with some scopes I've had 10-15 years. It seems like their tension springs have gotten weak over time and they don't always hold consistant center. Another case of half moa to 2 moa and a scope swap fixed it.

Enlighten me please...

Bb

Burley, I read somewhere not to mount within 1/2" of either side of the saddle or within 1/2" of the power ring. I mounted a Weaver 3-9 once with the rear ring up next to the power ring and with the prescribed 18" lbs. of torque, could barely turn the ring. Makes sense the same could occur with the other internals.
John

Subscribed!

Burleyboy,

It depends on several things: where the stuff inside the scope is located, how thin the tube-walls are, and how much you tighten rings.

Over the years I've seen all sorts of odd things happen to scope because the rings were around an important place, such as the reticle cell in a 6x scope. In most 6's the reticle's right in front of the rear bell, and if you put a ring around that area it can do some strange things, including break the reticle if the ring is tightened too much.

Have also seen variables turned into fixed-powers, and several erratic suddenly "fix" themselves when moved, or the rings loosened somewhat.

Kingston, subscribed to what?

Hmmmm.

I'm using Weaver rings and bases to mount a Leupold fixed 4x33 on a Model 70 in 30/06. The scope has a pretty short tube, and the action is so long that the rear ring is barely forward of the rear bell and the forward ring is barely aft of the front bell. Eye relief is all wrong, but I can move the scope maybe 3/8" to adjust for it. I've got a one-piece base on order, and I'll post back when I get it installed and the scope re-mounted.


Okie John

I had a similar concern while mounting a new scope recently. To get the eye relief right I ended up mounting the scope with only about 2 mm gap between the ocular bell and the rear ring. So I wrote to the manufacturer's customer service just to be sure and the following is the reply I have received from one of the reps.

"That should be fine. We don’t have a like a specified distance that you should have." "Having a slight gap in place is an ideal situation."

I will be zeroing in the rifle this afternoon so we will see how it performs.

I'm glad that others have been noticing the tube length issue. Recently, well let's say within the past few years, I've been noticing that I often cannot mount the scope that I had intended to use on a particular rifle using the mounts I wanted to use, due to the shortness of the scope tube. These days, I mostly use nothing but Leupold scopes mounted in Talley mounts. I've often ended up mounting a scope not because it was optically or functionally what I wanted to use, but have had to select a scope based upon what would fit on the bridge of the rifle. I have not asked Gary Turner at Talley if he makes extension rings or not. Even if he does, I'd prefer not to have to go that route. Is there some optical reason for the short tubes these days?

TT

tsquare, I don't know how many times in the last 3 or 4 years that I have had to "settle" on a scope/ring combo as opposed to just bolting up what I really wanted in the first place. For instance, I had a Weaver fixed 6 that I got for a s/a Ruger MKII ultralight .308 and there was just no way I could mount it and the scope be anything much more than decoration. Same with the 2-7X33 Leupolds, the 2.5-8X36 (slightly better) and a host of other scopes. I have often wondered if this has anything to do with the proliferation of the AR platforms and other tactical type offerings. Not all, but most of the younger shooters entering the sport today seem to have little interest in the Winchester 70s, Remington 700s, etc. and maybe the optics market is just reflecting that.
John