Smith and Wesson 500
You will haver to define if "biggest" means caliber or overall size.
Depends on what you mean by biggest. There is a revolver in .600 Nitro Express, and 12 guage pistols.
It depends on whether you mean legally, or what is the biggest handgun available, and whether you mean handgun size, or caliber size. The largest commonly available caliber is .45 ACP, however, .50 AE is also fairly common. That said though, there is also a handgun available in .600 NE. Most states don't have restrictions on caliber, however, some may.
You will have to be more specific. Handgun, shotgun, rifle, crew served?
NO, biggest is an adjective; the superlative form of big (big, bigger, biggest).
The biggest reason is that it is illegal (in most of the U.S. anyway)
A Siberian Tiger is the biggest big cat
The adjective 'biggest' is the superlative form for the adjective 'big': big, bigger, biggest
big
The biggest "big" cat is the Siberian Tiger.
The smith & Wesson .500 or the Pfeifer Zeliska .600 Nitro Express revolver its a debatable topic
It depends on where you live. In the U.S. in most states, there is no specified limit. In Tennessee where I live, "handgun" is basically defined as any gun designed to be fired with one hand or something very close to that.