POSSIBLY- and this is a stab in the dark- 7.62 NATO- similar to the civilian .308 Winchester. RG is a headstamo used by the Radway Green ammunition plant in Britain. In 1950, the standard rifle used the 7.62 NATO cartridge. Again, just a guess.
in a gun store
None. There were cannon in 88mm, but that is 346 caliber
any gun or sporting store
NEVER FIRE AMMUNITION IN A WEAPON IT IS NOT CHAMBERED FOR!!!!!!!!!!!!!!!!! No, No, NO
Gun shop, on line ammunition sales. Caliber is 6.5 Carcano.
Only use the caliber designed for that particular gun unless you want the gun to blow back into your face. It is never safe to interchange ammunition not specific to the caliber of weapon you use.
The first ones had six barrels that used .58-caliber ammunition.
Very simply, you have to know what caliber your gun is. If you don't know, take it to a reputable gun store and ask them to look at it.
No, never attempt to fire ammunition in a weapon it was not designed for!.
The caliber should be clearly printed on the barrel of the weapon. If unsure, consult a gun smith.
IF a rifle is chambered in caliber .35y magnum, yes. Among others, Marlin made a lever action .357 magnum rifle.
A ".45 caliber" can be a gun that uses .45 caliber ammunition or it can be a round of that ammunition. There are several specific calibers of small arms ammunition that are all generally called ".45 caliber." They have bullets that are roughly .454 of an inch or 454/1000 fractionally. A famous .45 caliber is the .45 Long Colt, invented in the 1870s and still popular today. It is used in revolvers. Another caliber that is the same diameter but a lot shorter in length is the .45 ACP or .45 automatic Colt pistol. It was made for use in the U.S. military's Model 1911 handgun, and it is still a popular caliber today in that gun and in other handguns. There are some rifles and carbines that use .45 caliber ammo, too.