That was former Heavy Gear line editor Marc Vezina himself, as I recall. I used the 3G3 rules for the Equipment Catalog at his request, though I tweaked the formula a little for my purposes. (And you changed the stock formula from 4 to 3.7, by the way.)
Anyways, it was a hiccup that was easily corrected if you wanted to. In the end, at my table we decided to make the higher DM value 5mm and 7mm Paxton rounds analogues to the 5.56mm and 7.62mm NATO rounds. The 7mm rounds in the main rulebooks were 7.62mm Pact rounds, and that worked for us on many levels.