Yeah generally the number refers to bullet diameter in metric or imperial. But as mentioned there are exceptions like .38 spl which is .357 and the 44 magnum which is .429. hmmm is that maybe why Smith and Wesson named their first 44 magnum the model 29?
Also remember bigger calibre does not necessarily equal more stopping power. The rifling rate/type, bullet design/material and of course velocity factored with calibre determines stopping power.
And be very careful to always match the calibre markings on your gun to the ammo you actually put in your gun. there are a few calibers that look similar and whose names are very similar but they are not the same!.
Example don't use .303 British in .303 Savage guns (or vice versa).Using the wrong calibre ammo and can result in a destroyed firearm and/or firearm user! BEWARE!
And with shotguns always make sure you do not mix/store different gauge shells together. I did a hunters safety course a few years back and they had a ruptured 12 ga pump as a teaching aid. The owner had accidentally mixed a few 20 ga shells in with his 12 ga ammo. He chambered what he thought was a 12 ga shell. It was actually a 20 ga shell. Later in the day he goes to fire the gun and gets a "click". He assumes he had forgotten to chamber a round so he racks the pump and chambers the next shell , this time its a 12 ga. The shell chambers pushing the 20 ga shell ahead of it down into the barrel. Well you can guess what happened when he pulled the trigger! It blew the barrel apart and cracked the receiver. Luckily the shooter didn't get killed but thats what that was really, just luck!
Also remember bigger calibre does not necessarily equal more stopping power. The rifling rate/type, bullet design/material and of course velocity factored with calibre determines stopping power.
And be very careful to always match the calibre markings on your gun to the ammo you actually put in your gun. there are a few calibers that look similar and whose names are very similar but they are not the same!.
Example don't use .303 British in .303 Savage guns (or vice versa).Using the wrong calibre ammo and can result in a destroyed firearm and/or firearm user! BEWARE!
And with shotguns always make sure you do not mix/store different gauge shells together. I did a hunters safety course a few years back and they had a ruptured 12 ga pump as a teaching aid. The owner had accidentally mixed a few 20 ga shells in with his 12 ga ammo. He chambered what he thought was a 12 ga shell. It was actually a 20 ga shell. Later in the day he goes to fire the gun and gets a "click". He assumes he had forgotten to chamber a round so he racks the pump and chambers the next shell , this time its a 12 ga. The shell chambers pushing the 20 ga shell ahead of it down into the barrel. Well you can guess what happened when he pulled the trigger! It blew the barrel apart and cracked the receiver. Luckily the shooter didn't get killed but thats what that was really, just luck!
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