I wouldn't even think about going after one with anything smaller than a 7mm Magnum, and even that I would find iffy, dependent on the type of bear. Try shooting one with a 5.56x45 or .223 Remington, as the previous poster suggested, and your final epitaph will be read in said bear's bowels.If the game in question is black bear,Then you will be well served by the 308 win,30-06,or a 7mm rem mag.If you are talking a grizzley bear,or alaskan costal brown bear then the demand on the cartridge changes dramatically.I would choose a 338 win mag as the minimum caliber and most alaskan guides choose the 375 H&H or larger because they may have to chase that bear into the willow thickets after being wounded by their clients.
One you can shoot accurately that meets or exceeds your state's minimum caliber restriction.
Single shot 50 BMG Yes, that would work. You can shoot one with whatever handgun you wish to use. Just be sure you can run faster than whichever bear you pick to shoot if you pick a caliber that does not kill it.
There are a lot of calibers that are able to shoot long distances the best rifle in the 30 caliber family are any of the 300's from the weatherby to the winchest er will do a great job on those long range shots
7.62mm
Best left to a gunsmith
Rifles: Lowest caliber = .357, highest caliber = .44mag Pistols: Lowest caliber = .38, highest caliber = .454mag or a .50AE
Best will be determined by intended use, your pocket book, your skills and what is available
The best caliber rifle is entirely dependent on what game you are hunting. For varmints (small pest animals like gophers, moles, and prairie dogs) as .22 LR would be appropriate. For deer and elk, I would chose one of the .30 caliber options, either 30.06 or .308. For moose, or cape buffalo, I might go up to a .454.
Best left to a trained factory representative.
There is no one single best caliber, but to get an answer, you need to be a little more specific. Rifle or handgun? Define long distance. 50 yards? 100 yards? 1000 yards?
With a rifle, the most stable position is either prone, or firing supported by a bench rest.
use hoppes bore snake in 22 caliber best i have ever used