Gary,
A slightly different mould, but I had to "beagle" the RCBS 30-180-SP to drop at .310", from a straight clip-on alloy. I seem to remember reading that RCBS uses an alloy to produce a .309" bullet, from a .30-caliber mould, thus a .310" or .311" bullet is not possible.
By the way, my 03A3 is in love with the 30-180-SP.