Unfortunately this is a downside of any straight fitted 'speed feed' as teeth have to hang down into the loader when potting up. The alternative is to raise the feed up which looks bad and will cause it to not be so secure.I've binned off using 160shot locklids with my rotor. Can only just get 140 in with the speedfeed on!
Maybe check out the High Capacity shells for the Rotor. They will give you an extra 50 capacity whilst bringing the size up to no more than a VL.
Best regards,
Tommy