Objective bell height above the bbl ?

[Varmint Hunter]

Is there any reason why I should not mount a new Zeiss 4.5-14x50 with the objective bell just a few thousandths above the barrel? The rifle is a Rem LSS in 300 RUM.

Using medium height Burris Signature rings and standard inserts, the bell touches the barrel. I was thinking of using the +20 inserts which will probably give me about .010" of clearance.

I could also switch to the Signature "high" rings which are about .120" higher than the medium rings but I'm not thrilled about using high rings unless it's necessary.

What do you think?

[geargrinder]

Originally Posted by Varmint Hunter

Is there any reason why I should not mount a new Zeiss 4.5-14x50 with the objective bell just a few thousandths above the barrel? The rifle is a Rem LSS in 300 RUM.

Using medium height Burris Signature rings and standard inserts, the bell touches the barrel. I was thinking of using the +20 inserts which will probably give me about .010" of clearance.

I could also switch to the Signature "high" rings which are about .120" higher than the medium rings but I'm not thrilled about using high rings unless it's necessary.

What do you think?

What about using the high signatures and lowering the scope with the inserts? You could gain some MOA if you offset them. To get the scope lower use the bigger offset in the front and the smaller in the rear. Meaning lift the rear a little, and drop the front a lot.

[Varmint Hunter]

Originally Posted by geargrinder

What about using the high signatures and lowering the scope with the inserts?

Now that's something I hadn't thought of.

Due to recoil induced flex of the scope tube, mounts, bbl, etc (on a 300 RUM); what would be the minimum air space needed to avoid contact between the objective bell and the barrel? I know all set-ups are different but how about a ball park figure?

[geargrinder]

Wow, what a question. Can't wait to see someone clearly answer that one.

I know I can somewhat answer by saying that the further apart you can get the rings, or the closer you can get the forward ring to the bell, the better it will be supported. Minimizing the amount of movement at the bell.

But, I'd really like to see if someone has ever quantified the movement/flex under different amounts of recoil.

That scope flexing video sure opened my eyes to the potential issues.

[Kevin Cram]

I don't know the scientific answer to this one but .01" isn't much clearance at all. It is clearing though and I don't believe there is that much flex at that portion of the barrel, but I normally like to have a little more clearance there just to be on the safe side.

[Varmint Hunter]

Originally Posted by montour rifles

I don't know the scientific answer to this one but .01" isn't much clearance at all. It is clearing though and I don't believe there is that much flex at that portion of the barrel, but I normally like to have a little more clearance there just to be on the safe side.

Hey Kev,

You may not remember me but I'm a groundhog hunter from L.I. I hunt in your area all the time. My buddy and I were at the shop twice and you did some accuracy work on this particular rifle.
Looks like I'm going to just order the high rings. I may even try the suggestion of using the .020" inserts with the fat half on top to minimize the scope height.

Hope all is well. - Charlie

[davewilson]

put the .010 inserts on the rear and the .020 on the front for a little scope lean. you could always put a lens cap on the front and have very little clearance for that "just right" look!