Scope and barrel vertical alignment.

[Baller]

I picked up a used Model 10 precision carbine not long ago and just recently finished building it. I’m new to bolt guns and am wondering about bore and scope vertical alignment. How exactly over the bore does it need to be? FWIW, over time, I intend to shoot long range and stretching this thing out. The rifle I bought came with a Ken Farrell 10MOA base. I bought a Weaver 20MOA base and Weaver 6 bolt rings. I mounted the new base and rings and it looked like this.






The scope was off to one side. I thought it was the rings. I contacted Weaver and they exchanged the rings without problem. I mounted the new ones up with the same problem. I got the same results with both bases. I looked a little closer and noticed the action was not level in the stock. It was canted in the direction of the scope offset. I straightened out the action in the stock, but the problem still persists. By the naked eye, it looks the same even with the leveling of the action in the stock.

Above are pictures before the new rings and adjusted action. The below are pictures of the action leveled in the stock with the new rings.







Any help into what I can look into would be greatly appreciated. Would it be wrong to cant the action in order to get the scope vertically aligned with the barrel? Is there something else that could be the problem? I don’t want to believe the holes drilled in the action, for the base, are the cause of the cant. Also, it looks canted to me, as opposed to misaligned. It’ looks like the scope is parallel with the barrel/action, just not vertically aligned. Thanks for any help you can provide.

Baller

[Robinhood]

We know nothing about the scope.

There are some things that can happen to an action if the barrel has been removed the wrong way. There are also instances where the mount screw holes have left the factory drilled and tapped out of alignment. If you look down the bolt raceway and everything looks straight, the next thing is to pull off the scope, rings and bases.

Screw the forward and rear most base screw back into the action, lay a long straight edge up against the screws. The straight edge should line up with the center line of the bore/barrel. Let us know what you found.

[Baller]

We know nothing about the scope.

The scope is a new Primary Arms 4-14x44 FFP R-Grid. In all the newer pictures, the scope was loose, laying in the rings with no tops on the rings. The scope fit perfectly in the rings. There is no binding or having to force it into place. As pictured, the scope is bottomed out and fully seated in the rings. If I am to believe the scope is straight and true, the rings, as a mounted pair, are also straight and true.

Screw the forward and rear most base screw back into the action, lay a long straight edge up against the screws. The straight edge should line up with the center line of the bore/barrel. Let us know what you found.

I'll see if I can fit in some time tonight after work to do this. I'll let you know what I find.

[Robinhood]

How exactly over the bore does it need to be?

Pretty darn close. From the looks of it, in your situation you would run out of adjustment fairly quick. Ideally you want the optical center of the scope to be on plane with the barrel bore.

Another thing you may want to try is using that same straight edge lay it along side of the action and compare the distance to the barrel O.D.. The barrel looks centered in the stock so I don't think there is an issue there.

However if we look at the mount hole alignment and the action to barrel alignment we can determine if the screw holes are off or the barrel action junction is the issue. And then there is the "tweaked action" thing. Looking at how it sits in the stock I think we can rule that out as well.

BTW have you tried to mount everything on the Ken Farrell base for kicks and grins.

[Baller]

I've got a side question. What are the wholes on either side of the action? You can see one in the last picture I posted of the side of my rifle. There is another one on the opposite side also.

[darkker]

Those are pressure relief ports, for when you have a case separation. Having a separation with them and a gun that has proper gas control, makes for a nice day.
Rifles without them, and/or with poor gas control and it can be quite unpleasant.

[Texas10]

Looking at that big, beautiful, polished granite counter top makes me think that it would make a perfect flat-plate to check, say, a 3 or 4 ft piece of one inch or inch and three sixteenths aluminum tubing for straightness.

I'd lay that nice straight piece of tubing into the rings and see if it points in the same direction as the barrel.

[redman]

If the mounting holes were tapped off center I would think you would see gaps in the base setting it on the receiver it wouldn't align properly either.

[redman]

Just adding to the above....I'm saying you would have had difficulty mounting the base if the holes were not aligned.

[Baller]

I figured it out. Don't bother asking what it was. Let's just say it was trivial.

Thanks for all the input people provided.

[FW Conch]

Scope centered over bore. That's the reason I never use rings that tighten from one side. No matter how much they charge for them. :-((

[Zero333]

I figured it out. Don't bother asking what it was. Let's just say it was trivial.

Thanks for all the input people provided.

Spill the beans. We wanna know anyway

Everyone of us has done something like this at one time, some of us more than once.

[drybean]

Tell us what did not fix it

[Baller]

Spill the beans. We wanna know anyway

Everyone of us has done something like this at one time, some of us more than once.

After doing a number of things to confirm the rings were aligned, I took everything off and just put the base screws in and they were canted off to the side. I put a level on the rifle and the whole rifle was canted as it sat in the bipod. Put some paper under one leg and it leveled everything out.

[Zero333]

Best way to remeber how to do something correctly is to mess it up, find the problem and fix it.
This way you stand a much better chance of doing it right the next time.

Like I said, we've all done dumb shit because we ain't perfect.

[adammiddagh]

I find it works best for me to level off the action / rail. Level the scope to that and use an anti cant level on the scope when shooting. If you do not worry about having a level with a "V" on it, you can get one for $5-15.

It amazed me how far off level you can hold the rifle it you don't have the anti cant device to double check it. My normal range setup tricks the eyes every time.

Also, on my first pillar bedding I mounted the action ever so slightly rotated the in the stock. With the action/scope leveled, i do not notice it.

[J.Baker]

Mind the rules guys.