The most common hand-gun caliber used to be 9mm Luger. Recently I bought a pistol and took a self-defense course. Now it seems the most popular caliber is the.40 Caliber Smith and Wesson.
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There are popular, and there are most common. The most common gun caliber is .22 rimfire, in terms of the total number sold.
Rifle or handgun?
The most popular gun made by Glock seems to be the 9mm for people who use it recreationally. Police officers, and the like, seem to prefer the 40 caliber.
50. caliber machine gun....period
.45 caliber Thompson Sub Machine Guns = Tommy Gun
the 12 guage is a caliber not a gun
.69 caliber Springfield
No. Very popular caliber since 1899.
The Smith and Wesson M&P 15-22 is the best weapon for a zombie apocalypse. It is an AR design which shoots the .22 caliber ammunition. The ammunition is the most affordable as well as the most popular.
a .45 caliber.
What caliber of man are you looking for? What caliber of gun are you looking for?
The short answer is no. The longer answer is, you might be able to get a .40 caliber cartridge to fire from a .45 caliber gun, but it may damage the gun, and even if it doesn't damage the gun, it will cause other problems. In general (with only a few exceptions) you should never try to fire any cartridge in any gun other than a gun designed for that caliber.
It is the standard .68 caliber