I've always played accelerator rifle and snub pistols having no effective recoil.
Trying to to understand the new mechanics here, the receiver soaks up recoil, hence the extra two points for snub and four for rocketry.
With three dice minus three, the handgun receiver easily compensates for the snub round, with a point to spare; the light handgun round at two dice also gets compensated for fully with the default handgun receiver. Or, for that matter, a heavy rifle four dice with a longarm receiver and it's six points.
Though with the heavy rifle, that's still a pretty hefty kick.
Anyway, light handgun, in theory, would have no recoil, and could be used in the same manner as a snub pistol.
Default damage for light handgun would be two to twelve, average seven, with snub, zero to fifteen, average seven and a half.
Enhanced wounding is six to sixteen, average eleven, and I'm not sure how a half dice works in this case, unless its three times six, minus three, plus six, so six to twenty one, average thirteen and a half.
Now I view heat and recoil rounding up dice, so consistency would mean that you'd do the same thing with effect.
Thirteen and a half isn't too far off from sixteen, meaning a human would have to roll for knockdown.