what is the difference between 38 super and 38 super comp
.38 Super In recent years, cases such as the .38 Super Comp, .38 Super Lapua, .38 Super RL (Armscor), and .38 TJ (.38 Todd Jarrett) became available transforming the .38 Super into an almost truly rimless cartridge. These "rimless" cases are somewhat of a misnomer, due to the case rim not retaining the same diameter as the case wall just forward of the extractor groove. A common example is the .38 Super Comp case, which has a semi-rim extending only .003-.004" per side, compared to standard .38 Super which has .007-.009" per side. The main reason for the development of new cases was due to the semi-rimmed .38 Super case not always feeding reliably from the double-stack box-magazines used in several semi-automatic pistols popular with practical shooting sports, such as USPSA or IPSC. The nearly rimless cases improve feeding reliability in these pistols but are intended to be used in firearms that headspace on the case mouth.[7] Other improvements found in some of these cases are modified extractor grooves and increased thickness in key parts of the brass for high pressure loadings.