Out of true scope mount holes vs barrel?

[hal9000]

So this question is an outgrowth of a conversation I just had with the owner of Stockade Gun Stocks. I was unaware but he indicated that a lot of older 110's had barrel threads that are out of true with the centerline of the receiver. I happen to have an old LA 110 that has a scope to barrel misalignment which I have always assumed was the result of the scope mounting holes being out of alignment with the centerline, but now I'm wondering if it's the barrel...

I guess my question is does it matter which it is and how would one easily differentiate between the two? Assuming it's the barrel out of alignment, is there any reason to not just compensate by using an adjustable windage scope mount to match the centerline of the barrel instead of the receiver?

Many thanks!

[pdog06]

Like you have been thinking, I too would bet on scope base threads being off center before barrel threads. I guess it’s possible but hasn’t really been too widely talked about.
Either way, a set of Burris signature Zee rings with offset inserts should line it up. The inserts can be used for horizontal adjustment as well.

[Dave Hoback]

Regardless of which, it’s pretty much the reason for having a floating bolt head.

[charlie b]

If you have a good straight edge you can find out. Just line it up on the side of the receiver on both sides and see if the muzzle is in the 'center'.

Will it still shoot? Probably, and might be as accurate as you need it to be depending on how far off it is.

[hal9000]

Yep, been using zee rings to good effect for years on this receiver. I just don't like how fiddly they can be. The straghtedge idea also occurred to me this morning, but thank you for the suggestion. Glad to know I'm on the right track.

This is an older rifle that's pretty beat up and I've never liked the OG stock ergonomics, so it's slated for an overhaul into a 6.5 chambering that is yet to be determined (254 win mag?... 6.5-300 wby?.... Something crazier?... Decisions decisions!). But I'm going to put some effort into making sure the receiver is worthy of investing in before I start! If any of you have suggestions for other areas of wear or trouble that I should look at please let me know!

[charlie b]

If it passes the 'simple' test, and if you want to invest a lot of money in it, like a high end barrel, then get the action trued. It is a fairly small price to pay for such an investment. The person doing the work can tell you if it is too 'wonky' to work with.

[South Prairie jim]

Regardless of which, it’s pretty much the reason for having a floating bolt head.

This ^^

[Robinhood]

The floating bolt head may help with offset. What about axial misalignment? If the firing pin is rigid, exactly how much can a floating bolt head help(bushing your bolt head might kill any benefit)? Looking further it only floats in one axis, perpendicular to the retaining pin. Seems to me that might help with even contact on the lugs...Then how much float can happen, Or does an modular bolt system reduce machining cost and reduce cost and inventory. Aren't we really talking about the loose tolerance in the bolt body to raceway allowing for some offset( but not of axis). Why do some rifles have a primer strike so far off center? Seems to me only the loose tolerances allow for any alignment correction. I'm not an engineer or an expert but those are my questions when I hear something like the bolt head fixes everything.

And then there is the progressive scope alignment issue with a barrel tenon that is not in the same axis as the action/scope mount screws. Floating Bolt head wont fix that either.

These are the reasons most custom action makers make everything parallel, perpendicular and concentric, even makers like Bighorn/Zermatt who claim a floating bolt head. Savages are probably accurate because of them straitening their barrels more than any other factor. Again just a layman's thoughts and beliefs.

[South Prairie jim]

The floating bolt head may help with offset. What about axial misalignment? If the firing pin is rigid, exactly how much can a floating bolt head help(bushing your bolt head might kill any benefit)? Looking further it only floats in one axis, perpendicular to the retaining pin. Seems to me that might help with even contact on the lugs...Then how much float can happen, Or does an modular bolt system reduce machining cost and reduce cost and inventory. Aren't we really talking about the loose tolerance in the bolt body to raceway allowing for some offset( but not of axis). Why do some rifles have a primer strike so far off center? Seems to me only the loose tolerances allow for any alignment correction. I'm not an engineer or an expert but those are my questions when I hear something like the bolt head fixes everything.

And then there is the progressive scope alignment issue with a barrel tenon that is not in the same axis as the action/scope mount screws. Floating Bolt head wont fix that either.

These are the reasons most custom action makers make everything parallel, perpendicular and concentric, even makers like Bighorn/Zermatt who claim a floating bolt head. Savages are probably accurate because of them straitening their barrels more than any other factor. Again just a layman's thoughts and beliefs.

Fair enough, I'm no expert either but I wouldn’t dump unnecessary money into a savage action that hasn’t been diagnosed with a problem.