.950 J D Jones
Depends on the application. If you mean power, the higher the caliber, the more powerful it is. for example, a .22 caliber rifle is much less powerful than a .50 caliber rifle.
We can't really answer that until we know WHICH 45 and which 50. In the case of a muzzleloading black powder rifle, the .50 with have more energy, all other things being equal. However, it could also compare a 50 muzzleloader to a .45-70 cartridge rifle, which is more powerful. Caliber alone only tells us the width of the bullet.
Rifle or handgun?
Any caliber can do the job. Most states regulate what can be used.
A VERY large caliber, VERY powerful rifle. It is the .577 T-Rex.
Both Shinsung and Sam Yang make a 50 caliber air rifle. The largest caliber Weinrauch makes is a .25 caliber.
Good rifle, good caliber for most uses. Did you have a specific question?
The standard caliber of a biathlon rifle is .22.
It is most likely to be a .32 caliber rifle since it uses .32 caliber ammo
30/06
Some guns yes, but most guns would require gunsmithing to change caliber.
At present the Sam Yang 50 Caliber "Dragon Claw". However this year 2014, other companies are starting to make 50 caliber air rifles. These rifles are capable of taking down deer.