Space Between Objective Lens/ Bell and Barrel

[concretus]

Hello,
I just installed a Burris Fullfield II 6.5-20 x50mm scope on my Winchester model 70 Target rifle in .308win. The barrel is a Wilson heavy barrel which is .985" in diameter at the subject area. I have a Burris 2-piece std base set and a pair of Leupold std high rings. I've had to shim the rings w/ about .025" of brass shims in order for the rings to work and now I have a gap between the Objective lens bell and the barrel of about .010. Is that an adequate gap. or should the gap be more to accommodate any change in the barrel as it is fired and heats up. Is there a rule of thumb of what the minimum gap should be? Is there a rule of thumb that states the maximum amount of shimming aloud when mounting a scope in scope rings? Any information would be appreciated.

 

[fredhorace77]

I maybe the only one but I have never heard of shims on the rings ...I have however shimmed scope bases. The only rings that I would use a so called "shim" would be the Burris posi-line scope rings which come with different inserts. As far as bell clearance I like to have atleast. 008" or more. Not for any particular reason other than it eases my mind

 

[Preacher]

As long as the bell is not touching the barrel, your GTG.........
Shimming inside the rings is a no-no..........
You'll put dents in the scope body, because now the rings are not round....

 

[Larryh128]

Good advice from both.

 

[itchyTF]

I've seen some high speed film of scope "vibrations" (don't recall the caliber) and it was impressive. I have some fairly close tolerances on some of my rigs, but not that close. Maybe not a bad idea to search for some of those videos and ask the scope manufacturer.

 

[Phil3]

This is a 50BMG, but there is a whole lot of 'flexin going on.

http://www.youtube.com/watch?v=s5pVya7eask

Phil