To a large degree the effect of the roll will depend on the type of gun being used and the type of powder being used. Roll a D20 on the Malfunction Table below, adjusting the result with any malfunction modifiers that apply.
NOTE! Older guns firing Smokeless Powder have a chance of exploding anytime a natural 1 is rolled.
Many of the older and cheaper guns are unable to safely and reliably handle the higher pressures resulting from the new propellants. A Used Gun that reliably shoots Black Powder loads can fire a properly sized Smokeless Powder cartridge. However, keep in mind that smokeless powder is almost 3x more powerful then comparable load of black powder. On any ‘To Hit’ roll of 1 a D6 is rolled. On a 1, 2 or 3 the gun simply misfires. On a 4 the gun is damaged and is inoperable but can be repaired with an hour of gunsmithing. On a 5 the gun is inoperable and damaged beyond repair. On a 6 the gun explodes in the shooter’s hand doing 1d6 damage to the shooter and 1d2 damage to anyone within 1 yard of the pistol.
MALFUNCTION MODIFIERS
Black Powder is dirty and creates fouling in the barrel and action that can increase the severity of a malfunction. For every 24 rounds of Black Powder shot WITHOUT CLEANING the weapon, the Malfunction Roll (below) is modified by -1
Cheap Guns have a Malfunction Modifier in their description (Usually -1 or -2_ That is applied to the roll on the chart below.
Old, Very Old and Neglected guns may have a Malfunction Modifier of -1, -2 or -3.
ALL Malfunction Modifiers ARE Cumulative!
NOTES:
(1) Bad Primer Misfire = Replace Cap or re-prime pan to try again.
(2) Bad Load Misfire = Weapon must be unloaded and reloaded and reprimed.
(3) Lock Jams = Requires wrench to loosen nut and reset.
(4) Breech Explodes = Get new gun
(5) Cartridge Dud = Eject cartridge, replace or cycle on to next.
(6) Fails to Eject = Cartridge case must be pulled or pried out.
(7) Cartridge Squib = Charge leaves barrel plugged with bullet. Must be removed to shoot again. Will need tools and a minimum of 15 minutes to repair.
(8) Cylinder Jams = Must be disassembled to repair.
(9) Hammer/Firing Pin Damaged = New parts needed
(10) Chamber of cylinder ruptures = Replace Cylinder
(11) Roll to Hit Ally = Apologize