As I said before, there are some rules from Ultramodern Firearms I’d like to use, if I may. All of them concern shotguns- different ways to handle range increments, choke, and different ammunition types (including non-lethal ones, of particular interest to John). The goal being to have versaltility over the sort of raw firepower that automatic weapons offer.
Range increments: Instead of taking a -2 to hit, “shot” ammunition instead takes a -2 penalty to damage for each range increment, representing the spread of the pellets. All other ammunition uses the standard rules.
A shotgun’s ‘choke’ is the level of restriction at the end of the barrel, which governs the spread. Open Choke weapons have no restriction; the range increment of the shotgun is halved, but the users gets a +1 to hit. Normal choke means that that the shotgun uses the standard rules. And full-choke weapons reduce the diameter at the end of the barrel, making the shot spread slower- instead of -2 to damage per range increment, the penalty is -1 to hit and -1 to damage. Some ammunition types can only be used with an open choke.
Ammunition types: Standard shells are 3 inches long. Shells that are 2 ¾ inches long and 3 ½ inches long are available, dealing -1 and +1 damage, respectively. Not all shotguns can use 3 ½ inch shells; all can use 2 ¾ inch ones.
Riot rounds: Deal same damage as regular round, only the damage is non-lethal. Purchase DC 5.
Slug: Same damage as a regular round, but the range increment applies to hit. Purchase DC 4
Slug penetrator: As above, but armor piercing: +1 to hit vs. armor or natural armor, -1 to damage whether the target is armored or not. Purchase DC 6
CS (tear gas): Tiny tear gas grenade. A 5-foot square is usually targeted; anyone actually hit takes 2d4 non-lethal. On the round it’s fired, the 5-foot square if filled; on the following round, all squares within 10 feet are filled. Fort save DC 15 or be nauseated for 1d6 rounds (as per errated tear gas). Purchase DC 12
CS Penetrator: As above, but 2d6 lethal if hit. Intended to go through door, etc.-if the damage equals or exceeds the hardness of the door, it goes through. Purchase DC 14
And, my personal favorite:
Dragon: Shoots a gout of fire, making the shotgun a miniature flamethrower. A 5-foot wide, 20-foot long line dealing 2d6 fire damage, reflex half, with a chance of catching on fire as per Chapter 7 of the core rulebook. Purchase DC 12.
As for the weapon, the Mossberg 500 ATP6C: Damage 2d8, Crit x2, Ballistic, Range increment 40 feet, Rate of fire single, purchase DC 14, Restriction Lic (+1). No stock, pistol grip, 2’4 inches long and 6 pounds. Can fire 3 ½ inch shells.
If I explained something poorly, feel free to ask. Character should be up later tonight.