Scope rings on M77 Mark II

[atitagain]

This might really sound like an odd question, but here goes anyhow.

I just purchased an M77 Mark II in .300 Win. Mag.
When I went to put my Bushnell 4X12X40 scope on it, I noticed the rings are not exactly the same.
One is higher then the other.
Looking at this gun, I don't believe it has ever been fired.
Bore is perfect, and there is no primer ring on the bolt face.
I have never used Ruger rings before, but this just doesn't look right.
Am I right, or is this just something different?
If I put the higher ring on the back, the scope lines up with my eye just right. But the front bell almost touches the barrel.
If I switch the rings around, the front bell is fine, but I have trouble lining my eye with the scope.
Do I just buy another higher ring?
Are they marked somehow as to height?
Or do I just take the higher ring with me and tell them I need another one of these?
I mean "It just doesn't look right!"
Thanks for any help. Even as simple as I think it might be.

[George Foster]

If your rifle has the Ruger rings then the rear ring is higher than the front one. That is the way the Ruger rings are set up from the factory and they are excellent rings.  If you look at the receiver you will see the milled base is taller in the front than it is in the rear.

[JPShelton]

As George Foster stated, if they are Ruger factory supplied rings, the taller one attaches to the rear receiver bridge while the shorter of the two attaches to the foward receiver ring.
 
If they are Ruger factory supplied rings, you want to be careful to not "mix and match" the caps or top halves.  Ruger used to give a warning against doing that.  In other words, the top half of one ring mount needs to stay with that ring mount and not be swapped to the other. 
 
I had a Ruger M-77 Mk II in .270 when they first came out.  I didn't have any clearance issues mounting a 3 X 9 Leupold Vari X II in the supplied rings.
 
I currently have a Ruger M-77 Ultralight in .250 Savage.  This is the predecessor to the M-77 Mk II but uses the same ring mounts.  This rifle has a 2 X 7 Leupold Vari-X IIc on it of the same Mid-80's vintage as the rifle is.  Again, no clearance issues.  I can see how I might have some if I used a scope with an adjustable objective, or scopes with larger objective bells. 
 
JP

[George Foster]

I have 3-9x -40's on two Mark II's and they both have 1/8" to 3/16" clearance between the objective bell and barrel.

[atitagain]

Thank you for the responses.
I have learned a few things.
One of which is in order to use this scope, I will need a set of medium or high rings.
And the new quest begins.
Finding a set of them.

Mitch

[tobster]

Just a heads up=Make sure your new rings are for the 77 and not a Ruger #1, as the rings for #1 rifles are the same height front and rear. Others here will know, but I think the Ruger rimfire rings are also the same height.