Cowboy Mounted Shooting Blank Ammunition
By Robert Morris

Cowboy Mounted shooting uses certified 45LC blank ammunition.  It can be lethal at close range, but harmless after about 35 feet.  All competitors use the same ammunition at a match. It is supplied by the match’s organizers to ensure there is no advantage to one competitor over another and that no one has brought a dangerous, non-approved round.


45LC is the designation for the ammunition used in the Colt Peacemaker that first came out in 1873.  It is often called a 45-40 for the 0.45 caliber (diameter of the bullet) and 40 for the grains of black powder in the case.


The Peacemaker revolver is often designated as the Colt SAA, Single Action Army.  It was used as the primary U.S. military sidearm for many decades and packed a powerful punch due to the large powder load and very heavy lead projectile.  The revolver was also heavily used in the Old West, but there were many other popular weapons and calibers.


In Cowboy Mounted Shooting rounds, about 35 grains of a modern black powder substitute are loaded in an elongated case.  The case is then crimped to hold the powder in.  The modern black powder substitute is less corrosive than the black powder used in the Old West.


The original black powder (80% salt peter (potassium nitrate), 12 % charcoal, and 8 % sulfur) was used in warfare by the Chinese by about 904 A.D. and was still dominant until near the end of the 18th century when modern smokeless powder came into use.  Essentially all modern firearms, except the very popular replica firearms, use modern “Smokeless” powder.


Black powder, whether the original formula or a modern substitute, burns incompletely in the cylinder and barrel.  About half of the powder exits the barrel as burning particles and the other half as combustion gases from the portion that has reacted in the revolver and has driven the unburned portion. The smoldering particles provide the momentum and heat that either causes the balloon skin to break from the impact of a particle or melt.  The result of either is a cloud of smoke and a broken balloon.


As the unburned particles from the barrel continue on their path the combustion process turns the remaining particles into gases.


The ammunition has proven to be amazingly safe.  No one has counted how many millions of rounds have been discharged in all types of arenas, spectator situations and conditions allover the country.  But, there have been no serious injuries to the author’s knowledge.  This is an amazing record.