Caliber is the diameter of the actual bullet in thousandths of an inch. However many times there is absolutely no rhyme or reason for naming some of the cartridges made today.



Here is a short list that was taken from Chuck Hawks web site.

The following list shows correct bullet diameters in thousandths of an inch and rifle cartridges that use bullets of each diameter. For an expanded list showing more bullet diameters and more calibers see the "Expanded Rifle Bullet Diameter List" on the Tables, Charts and Lists Page.



.172" - .17 HMR
.223" - .22 Short, Long, Long Rifle
.224" - .22 WMR, .222 Remington, .223 Remington, .22-250 Varminter, .223 WSSM
.243" - .243 Winchester, 6mm Remington, .243 WSSM, .240 Wby. Mag.
.257" - .25-06, .257 Wby. Mag.
.264" - 6.5x55, .260 Remington, .264 Win. Mag.
.277" - .270 Winchester, .270 WSM, .270 Wby. Mag.
.284" - 7mm-08 Remington, 7x57 Mauser, .280 Remington, 7mm Mag. (all)
.308" - .30 Carbine, .30-30, .300 Savage, .308 Winchester, .30-06, .300 Mag. (all)
.311" - 7.62x39 Soviet, .303 British
.321" - .32 Winchester Special
.323" - 8x57JS Mauser
.338" - .338-57 O'Connor, .338 Mag. (all), .340 Wby. Mag.
.358" - .357 Magnum, .35 Remington, .35 Whelen, .350 Rem. Mag.
.375" - .375 Mag. (all), .378 Wby. Mag.
.416" - .416 Rigby, .416 Rem. Mag., .416 Wby. Mag.
.429" - .44 Rem. Mag., .444 Marlin
.458" - .45-70, .450 Marlin, .458 Win. Mag., .460 Wby. Mag.

As you can see some cartridge names such as the 44 calibers do not match up with the actual bullet diameters.


AS far as a long range deer cartridge goes you would be hard pressed to beat the standard .270 Winchester. It will shoot as flat as anyone would need it to shoot.

I would caution you against shooting at live animals until you have done a lot of practicing. I say this because too many people are getting into this "magnum" craze and want to shoot animals at ever greater distances and do not put in the time that it takes to actually be proficient at extended ranges. The fact is that most deer are taken well inside 200 yards with rifles. I only mention this because you stated that you do not know much about bullet diameters and such and that leads me to believe that you have done very little shooting with rifles.