This is a physics model I created with Marathon Physics Model Editor 1.1.
First I made a bunch of minor tweaks to the AR-75. I increased the damage done per bullet 8 to 30 (your life is about 150 on that scale, the Trooper's ARs do 15 damage per bullet) and I reduced the spray range by half. Then I modified the Pistol and the Flamethrower; the Flamethrower's second trigger now throws you across the room, and the .44 Magnum... well, you can find out why I named it El Pistol for yourself.
Well, I guess Ill tell you. Trigger fires a projectile equipped with a light anti-gravity generator that activates when placed inside the target, causing a large explosion. Trigger 2 fires a secondary projectile equipped with a larger generator that wipes out everything within a five meter range of the point of detonation.
I crash tested this on AOL for about three months; it gained almost five hundred dowloads. Please send any questions or comments or hate mail to me.