Greg, I have a number of sizing dies for each calibre, .177. 0.20, 0.22, 0.25.
For example in .22 cal I have 0.2190"/5.56 mm, 0.2180"/5.537 mm and 0.2175"/5.524 mm.
They are all old Beeman dies not sure who made them (Beeman never made anything).
I have a little gadget to put them in and push the pellets through. But all I do now is to push them through with a knitting needle of appropriate tip profile to suit each particular pellet. It is not hard even with pellets like Eunjins. The >25 JSB 33.9 gr Heavy Kings are easy.
Mostly I only use the smallest of the dies. ............. Skirts only have to be barrel groove size of a tad larger for PCPs.
Kind regards, Harry.