20 Fergusson Ace
Encyclopedia
20 Fergusson Ace is a wildcat centerfire rifle cartridge based upon the 20 BR
which has a blown out shoulder angle of 45 degrees. It was designed and developed by legendary gunsmith and varmint hunter Gaylon 'Ace' Fergusson and predates the .204 Ruger
factory cartridge. Having the blown out form and steep shoulder angle the Fergusson Ace family of cartridges have approximately 10% more powder capacity than their parent cases. This gives very high velocities when paired with the correct propellant blend and charge. An example round recorded 4220fps with a 40 grain V-Max when fired from a 24" pac-nor 1-11"twist barrel. This performance comes at the cost of the barrel with life expectancy in around 500-600 shots depending upon the choice of steel grade. Brass is usually taken from .22 BR Remington
stock, then necked down to .204" and fire formed in the custom chamber of the rifle. Major drawbacks are the scarcity of both reloading dies and chamber reamers in this format.
20 BR
20BR is one of the many 20 caliber rifle cartridges known as wildcats . It is basically a .22 BR Remington case necked down to accept a .204" diameter bullet maintaining the same shoulder angle and overall length...
which has a blown out shoulder angle of 45 degrees. It was designed and developed by legendary gunsmith and varmint hunter Gaylon 'Ace' Fergusson and predates the .204 Ruger
.204 Ruger
The .204 Ruger is a centerfire rifle cartridge developed by Hornady and Ruger. At the time of its introduction in 2004, the .204 Ruger was the highest velocity commercially produced ammunition, and the only cartridge produced commercially for bullets of .204 inch/5 mm caliber.-Characteristics:The...
factory cartridge. Having the blown out form and steep shoulder angle the Fergusson Ace family of cartridges have approximately 10% more powder capacity than their parent cases. This gives very high velocities when paired with the correct propellant blend and charge. An example round recorded 4220fps with a 40 grain V-Max when fired from a 24" pac-nor 1-11"twist barrel. This performance comes at the cost of the barrel with life expectancy in around 500-600 shots depending upon the choice of steel grade. Brass is usually taken from .22 BR Remington
.22 BR Remington
The .22 Bench Rest Remington cartridge, commonly referred to as the .22 BR Remington, is a wildcat cartridge commonly used in varmint hunting and benchrest shooting. It is based on the .308 x 1½ inch Barnes cartridge, necked down to .22 caliber, lengthened by .020 inches and with the shoulder...
stock, then necked down to .204" and fire formed in the custom chamber of the rifle. Major drawbacks are the scarcity of both reloading dies and chamber reamers in this format.