That all depends on you, and what you want. Are you looking for a plinker, a serious hunting rifle, a SHTF weapon, something collectible, what?
Mosin Nagants seem to be pretty popular these days. One might consider those pretty essential.
You don't. Every part in the rifle is essential.
to be able to have more water to replenish on its own
if you dont know that then you should not own it.... the barrel should break over and you load it there
No.
for a rifle it is thought to be a .50 calibre but a gun company made there own for there own sniper rifle the .408 calibre
Yes it just depends how well you place the pellet and the fpe on the rifle a head-shot on a raccoon is good and heart and lung shot is good but you should place the shot at only how good the gun and your own air rifle about 25-30 yards. Your rifle should have at least 1000 feet per second.
Yes
Essential nutrients are needed for an organism to survive. Each organism has their own essential nutrients.
Each one has its own unique characteristics
18 years.
No
no