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.
The standard caliber of a biathlon rifle is .22.
7.62mm
a .22 caliber
Best left to a gunsmith
A .177 caliber air rifle has very little recoil.
.223 caliber or 5.56mm.
No You could build a rifle in .306" or any other caliber but you are likely referring to 30.06. A 30.06 rifle is referred to as "30 Caliber" but to be accurate it is nominally .308"
Yes, I can. A Barrett M107 is a .50 caliber sniper rifle.
The Dragunov (note corrected spelling) sniper rifle is in caliber 7.62x54mmR. This is the same caliber at the Moisin-Nagant 91/30 rifle.
50 caliber
Best will be determined by intended use, your pocket book, your skills and what is available
value of a model 49 ithaca 22 caliber rifle