I 'modified' things a little for the heavier weapons that I put into play.
ME29 from Weapons Law: Firearms is the highest chart for the .50 cal BMG round (as fired by the beloved Browning M2). the .50 is a 12.7mm... so for 20mm I doubled the hits (but not the crit) of ME29, 30mm is x3 and 40mm is x4.
Perhaps not the best method, but it's what I had.
Needlers and grenades/explosives are right outta SM:T for the most part; for my home brew I just present them with different names. Instead of a Mk1 greande, I call it a class 'A' is all.
All the rest of the guns are pretty straight forward for the WL:F book, each is assigned what I've deemed to be the appropriate chart and think I came out pretty damn good and with what I wanted.
MDC seems to like it well enough and still hoping you, LM, find the time to look it over too.
AAA
Did you find everything you needed in SM, or did you need to "Make it up"?