Wait wait wait!! Uh... Yeah.
I don't have and special rules for wildcatting or handloading. With most wildcats, you're looking at maybe a 10-20% increase in velocity over a parent case. There's really not a lot of reason to make rules for that kind of thing. You give it a +1 Power, or bump it up a range level and call it whatever and that's pretty much all you'd need to do as far as that goes.
But I do have rules for a few specialized wildcat cartridges, namely the Whisper series. They're in the Ammunition by Caliber section.
As far as handloading rules, you could say that with a Handloading Kit (say, like a
hand press, at about 100¥ with a couple of sets of dies, and it will fit in a backpack) you could pump out, say, 50 rounds an hour. With a Handloading Shop (like a
progressive press, about 600¥) you could do about 1,000 rounds and hour, and with a Handloading Factory (20,000¥) you could pump out, say, 50,000 rounds an hour. There could be all kinds of levels between, it's up to you. With the kit and shop, you could also throw some skill into it to bump up the rds/hr count.
The sabot version of the 7.62x25mm is the .223 Timbs (why it has its own name, I don't know). The .22 Reed Express is a necked-down 7.62x25mm, or .223 BOZ-lite, and is pretty much identical to what I had in mind for the .227 HK. Neat, though. $210 for a drop-in barrel (twice as much as I paid for the gun!). Hmm...