Today we have the original Remington Model 51, the pistol that inspired the recent (2014) R51. Made in .32 caliber and .380, the Model 51 was ingeniously designed to be as compact as possible. Its “hestitation lock” action permitted its slide to be slimmer and lighter; the return spring went around the barrel, not underneath it as with most pistols, lowering its profile. Its single-stack, seven-round magazine sacrificed firepower in favor of trimness. The Model 51 was supposed to be so ergonomically perfect that it was billed as “self-aiming.” Therefore, it had only the most rudimentary of sights, which weren’t big enough to snag on anything, contributing to its excellence as a pocket pistol. About 64,000 Model 51s were made.