[Legbreaker]

Originally Posted by TiggerCCW UK

I seem to remember seeing rules for AP ammo in a supplement somewhere where it stated that the damage was reduced by one dice but pen was doubled, but I may have dreamt it.

Not quite....
This is from the referees screen (or more accurately the booklet that comes with it).

Enhanced Damage Rounds: These rounds include a broad class of small arms rounds specially-designed to trade off penetration for increased tissue damage, usually by causing the round to widen, flatten, and/or fragment. Special rounds include hollow-points, mercury loads, reversed wadcutters, dum-dums, and a number of proprietary designs too numerous to mention. Such rounds are not suitable for military use (as they violate a number of international accords and their inferior performance against body armour makes them less suitable for most military firefights).
Special rounds are available only at the referee's discretion, and only in calibres between .22LR and .45ACP. They weigh the same as normal rounds, and cost the same. Availability is up to the referee, but they cannot be more common than the round they are based upon.
Add 1 to Damage value of enhanced damage rounds, but add 2 to the penetration value. When the penetration number equals or exceeds the modified damage number, it becomes Nil. For example: A standard 7.62mmN rounds has damage of 4, and penetration of 2-3-Nil. With enhanced damage rounds, the damage becomes 5, and the penetration 4-Nil (2-3-Nil plus 2 becomes 4-5-Nil, but since 5 equals the damage, value, it becomes Nil). The round will do more damage, but is less effective against body armour.