Finally got this old girl out to the range again since I was meeting a friend at one of my local clubs to shoot a few rounds together. Tried the 314299's sized down to .311", then some 311284's also sized to .311", then on an impulse I loaded some little Lyman 125 grain GC spitzer boolits that I had on hand that I shoot in my custom built bolt action 7.62x39mm (an old Ideal #311359 from memory?). The '299's put 5 rounds into about a 3 1/2" round group at 100 yards about 10" low of point of aim, the '284's were fairly dismal and put 5 rounds into about 6" or so also low of POA. The real surprise for the day were the those little 125 grainer spitzers ... they shot right on point of aim at 100 yards (the rifle is zeroed at 100 yards with LC Match 173 grainers) and the first 4 rounds went into a nice little cluster of about 2" and then of course I pulled shot #5 low right and ended up with about a 3" group. All were loaded with 18.0 grains of old Hercules 2400 in WW cases with WW LR primers. The full length sized cases were then neck expanded with an RCBS expander die using a .310" plug. More testing needed of course, but it was a great first result with cast in this old Springfield ...
The 5 rounds at 100 yards with the little 125 grainers ...