How much clearance is enough re:scope to receiver?

[Sev89]

Never really had to worry about this up to this point, but, I have a Bushmaster BA50 in .50 BMG. Mounted on top of it is a Nightforce Benchrest scope in a Larue Tactical mount. The initial spot on the receiver where the scope was mounted, left a gap between the bell of the scope and the receiver rail so small, that a business card wouldn't fit in between the two. I've mounted it further forward to (hopefully) solve this issue, but the question remains; How much clearance between the scope bell and receiver is considered enough on a big bore rifle?

 

[antco]

I don’t have anything that recoils and booms like a fifty, but I consider it good to go if I can see daylight through the gap. Your picture looks fine to me.

However, by moving the scope forward to correct this issue, have you created a new issue in relation to your cheek weld and the scopes eye relief?

 

[Sev89]

However, by moving the scope forward to correct this issue, have you created a new issue in relation to your cheek weld and the scopes eye relief?

I -think- I’m fine in that regard. I still get good cheek weld, and only have to move my head forward by an inch or so to get clear sight picture.

 

[Sticky]

To receiver, you should be fine. It does not move like the barrel itself. I'd be much more worried about scope to barrel clearance and you have no issue there. Your scope is mounted pretty far rearward, I'd not be concerned.