I've just completed parts acquisition for my Ruger 10/22 small game rifle. And I've run into an ignorance problem. This is my first firearm on which I use a telescopic sight.

Telescopic sight mount is Weigand's Integramount. Scope alignment with rings becomes a non-issue. That's good.

Scope is a Nikon Buckmaster 4x40, the largest objective lens scope with one-inch barrel the mount accepts. That's good.
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I have no special tools to accomplish the following.

1. While scope can be aligned perfectly with mount's rings, this may not assure mount aligns with axis of bore. How do I do this?

2. Having successfully aligned mounted scope with axis of bore, how do I true/square crosshair sight picture with rifle squared to target? What I mean is if I rotate scope barrel axially to superimpose crosshairs on a rectangular bullseye, this does not address whether the rifle is square before I rotate the scope. If I don't rotate from a squared rifle, I'll have no idea what I'm rotating to. I could clamp the rifle to a rifle rest on a shooting bench. Or I could clamp the rifle to a rifle cleaning fixture on a shooting bench. But why should I assume the bench is square to anything, or any fixture will automatically align a rifle squarely to fixture's base?

I'm getting a headache. Am I worrying about nuances that don't matter?

Hello,
Unless you suspect that the base/rings/etc. are a great deal off from the axis of the bore, I would say your concerns do fall into the nuance category. Yes, the base screw holes, grooves, or whatever you may have on your rifle should line up squarely with the axis of the bore, but most unlikely to be perfect. Adjustment of the scope elevation/windage will compensate for most normal out of alignment you may encounter. Perhaps I misunderstand your questions, but if the little bit of out of alignment is the issue, again that can be corrected w/ the optics adjustment. Perhaps others have more definitive answers than I have given??

martin

quote:

Originally posted by MFD:
Hello,
Unless you suspect that the base/rings/etc. are a great deal off from the axis of the bore, I would say your concerns do fall into the nuance category. Yes, the base screw holes, grooves, or whatever you may have on your rifle should line up squarely with the axis of the bore, but most unlikely to be perfect. Adjustment of the scope elevation/windage will compensate for most normal out of alignment you may encounter. Perhaps I misunderstand your questions, but if the little bit of out of alignment is the issue, again that can be corrected w/ the optics adjustment. Perhaps others have more definitive answers than I have given??

martin

I have no idea if we are talking about small problems, or a series of small problems that are collectively a large problem. Since the rifle relies on precise delivery of a bullet to accomplish its purpose, and I have no experience with needing this sort of precision -- minute of dinner plate at 75 yards is adequate for whitetail and elk in my big game area -- I'm attempting to reduce variables as I am able, without driving myself too nuts. I think I'm concerned that without squaring/truing to the best of my ability, normal variables, such as canting the rifle, rifle being used right-hander and left-hander, will cause significant and unanticipated changers in point of impact at longer ranges.

I'd suggest that your rifle should be set up firmly in a benchrest set-up or a cleaning cradle. (I clamp mine in a bench vise with padded jaws) You can level it by using small bubble-levels at various points (both vertical and horizontal) on the receiver, stock, etc. A small bubble-level on the top turret cap of your scope will tell you if it is level with everything else. This may take a little adjusting and re-adjusting until you get everything level.

Bore sight the rifle on some close point (25 to 50 yards), make sure everything is still level, and then peek thru the scope to see if the crosshairs are close.

This all sounds complicated but takes only a few minutes.

It will also help if you optically center the crosshair before starting. If you don't know how to do that you can center it mechanically which should be good enough.

Don't give up. As I said, it's not hard to do.

Good Luck

Ray

This is how it's done if you want to know your rings are on bore C/L I do it to all of my personal rifles.

Level the front ring


The next three photographs show a jig that is 1" dia. and is very long with a plum-bob in one end and sharp on the other....used as a visual ref. for bore/rifle C/L






This photo shows a set of level lines on the wall to aid in scope cross hair alighnment


Use a two pc. jig to alighn the two rings together


Then line/lap and you have rings that won't mark a scope and are on bore C/L

quote:

I've just completed parts acquisition for my Ruger 10/22 small game rifle

The barrel/receiver joint on a 10/22 is a crapshoot- I've had the factory barrels fall out of the receiver when removing them, also had to tap them out with a dowel; same in reverse when installing an after-market barrel. My point is they seem to shoot very accurately anyway, and the range at which they're used doesn't open up any wide error anyhow.

I'd put a scope on it and go shooting.

OTOH, Ted Horn and others above have provided fine, studied examples of what is a definitive answer to your question. Excellent.