I've recently acquired a 650 for making 221FBs and 20 VTs from LC brass.
I have a Dillon 1500 trimmer and shorty die station arriving tomorrow.
However I've found that 221 FB and 20 VT trims dies are unavailable.
It seems reasonable to convert regular FL dies to trim dies by boring the top of die to accept the trimmer blade, cut the shaving vents, and thread the top OD 13/16 x 20 to attach the trimmer assembly.
Has anyone done this? Am I missing anything?