Melvin, welcome to the 'fire!
I'm no expert and don't know the proper terms but I'll try.
There is a pin on the bottom of the bolt that reaches inside the action. When you "cock" the rifle, the pin on the bottom of the bolt slides an internal cylinder to the rear so it can be held against spring pressure till you release it by trigger.
Squeeze the trigger and that captured cylinder bumps forward hitting the valve and releasing the air pressure to the barrel/pellet.
The spring pressure is not adjustable.
A piece of leather the size of a 50cent piece to put against the bolt for cocking may help..
Good luck!
