If you are looking for a quiet air rifle, then look for one that has a "shroud" on the end of the barrel. An air rifle "shroud" on an air rifle is like a silencer on a firearm only it legal to have one on and air rifle in most places. The Shroud is often called a "noise dampener". Gamo offers the Whisper model that clams to reduce the sound by 52%. There are others that are much more quiet but they can be very expensive. As an example I own an Air Force Condor that has a full barrel Shroud with 5 baffles in the shroud. It's very quiet but expensive, costing over $700. The Benjamin Marauder is also a quiet air rifle with a full shroud at a cost just over $500.
I suggest you look at the following web page.
The superlative form of the word quiet is quieter
Mitsubishi Electric. NZs quietest air
A digital clock is the quietest.
The RabbitAir BioFresh and Blueair are both known for being extremely quiet.
An Air Rifle is either a BB rifle or a pellet rifle. It uses air or gas to propel the projectile.
The quietest in the group are all of them.
A sporter air rifle and what?
Are you asking how do you swap and air tank on an air rifle, or swap for and air rifle? In most air rifles you put it on safe and swap out the tank by unscrewing it and replacing it.
can i ship air rifle to trinidad and what i need
When you say Air Rifle you are referring to a pellet rifle not a firearm. At present there are no 300 Cal air rifle being made.