The version of the .45 Colt as of 2014 differs from the original cartridge case in that the rim is significantly larger (with a groove immediately above it) and the internal aspect of the primer pocket is surrounded by solid brass instead of protruding into the powder chamber. This "solid head" case is stronger and resists deformation of the primer pocket. Some commercial and custom revolvers and single-shot pistols (such as the Ruger Blackhawk, T/C Contender and others) employ high-pressure loads that are dangerous in the Single Action Army and other vintage arms chambered for the .45 Colt cartridge, especially 19th-century "pre-smokeless" revolvers, which should be fired (if at all) with black powder only.