I had a set of rings that were 3/8" and 11mm.

The side clamp plate was marked with a raised 'dot' that showed the 3/8" fitting.

Reverse it around to fit 11mm dovetail.

But...the actual shape (profile) of 3/8" and 11mm is different too.

The 3/8" bits might (sort of) fit the 11mm, but will not be a nice matching shape that would allow a good tight connection.

The side plates that do the clamping may be made with the correct shape depending on which way you fit them, but the other side of the ring or mount has a sort of 'hybrid' shape that fits either shape dovetail groove. Not a good thing to use.

For my use (benchrest) I only use actual 11mm fittings. I want my scope firmly and accurately held.

For a fun gun and plinking it probably makes little difference...although if you have an expensive scope you would really want the scope/rifle connection to be a good solid fit.

I could not find a picture of the underside for a later model AirKing mount. 

Using the pointed grub screws on the aluminium rail is probably fine and I expect they may line up with a predrilled hole and could possibly act as a stop pin though on mine the threads are not long enough.

When mounted directly on the  rifle chamber there is a real risk they will damage the finish and highly likely to move and gouge the metal and I recommend removing the screws completely.

For anyone interested - Where there is no stop pin or stop hole then clean the mount and dovetail grooves then Loctite sparingly along the contact face, I have done this with a 4 screw mount on a high power Crosman and it never moved and it also disassembled easily. Not a cheap option buyng cleaner and loctite but less risk than drilling or machining rifle parts.