You will have to define who "they" is.
Winchester mod 9422 XTR = 50 cm.
By US federal law, "normal" rifles cannot be less than 26 inches long overall or have barrels less than 16 inches long. Barrel lengths between 18 and 24 inches are normal, though some barrels are longer, and overall lengths between 38 and 48 inches are common.
That depends what the barrels are of and how much the individual barrels weigh.
Rifles and shotguns are both considered long guns.
The longest rifled barrel is probably the US Navy 16 inch rifles mounted on battleships-with barrels 66 feet long. Land based- the M65 Atomic cannon- with a 42'9" barrel. For shoulder arms, many muzzeloading black powder rifles used barrels in the 46 to 48 inch range. The Barrett .50 cal sniper rifle has a 29 inch barrel- and most civilian sporting rifles are 26 inches or shorter. Longer does not always mean better or more powerful.
That depends what the barrels are of and how much the individual barrels weigh.
long rifles rifles and hand guns
alright these are the most obvious pistols, shotguns and rifles. rifles are guns that fire bullets down a barrel that has spiraled groves aka rifling and they usually have long barrels, the shotguns send a lot of little beads all over the place and are very powerful when up close and personal, the last pistols are designed to be operated by one hand but are not accurate over long ranges.
US Army long arms (rifles/muskets) were Made In The USA. Confederate States of America (CSA) long arms were primarily IMPORTED (from England/France).
about 44.7 days
Rifle, handgun and shotgun can all have "long" barrels
if im right 20 days