Ever wanted to use the weapon on the front cover of The Ultimate Doom™? Now you can.
The Machine Pistol is a Pistol replacer that fires rapidly, at the cost of accuracy and a Duke Nukem-style reloading system. You will no longer be able to snipe with your starter weapon, but it benefits from being able to fire without wasting two bullets per trigger pull, unlike the Chaingun. Here is a download button to try it out yourself. The file is extremely lightweight at only 48kb, so you have nothing to lose by trying it out and seeing how it performs.
If for whatever reason you would prefer that it replaces the Chaingun instead of the Pistol, Ac!d has helped in a big way by providing an update to the mod that makes it so you can choose to have it replace the Chaingun or the Pistol with the change of a single CVar.
Special thanks to sonik.o.fan for making the weapon sprites, and to Skelegant for making an awesome firing frame that fits the weapon sprites.