Feeding problem Savage 111 detach mag

A guy on another forum who cannot get into this one has the following problem:

"Center feed detachable magazine in 9.3x62.

Loading some 220 gr RN cast bullets for indoor plinking (10 gr Trailboss)

Magazine hold 3. If you load 3, two feed fine the third angles up and jams
If you load 2, first one works, second jams.
Load one and it jams.

I'm guessing spring pressure in magazine goes down with less shells and doesn't "pop" the last round up (It is not CRF of course)

Guessing they use the same spring for all calibers. Anyone have one in 375 Ruger ? (heavy cartridges as well) Thanks!"

You are at the correct place to get an answer. I don't have any experience with this caliber but have tweeked the lips of the magazine to resolve similar issues with other calibers.