mechanical blowback operated marker

[gas_axe]

Hi, I have a T68 marker, which I beleave is a "mechanical blowback operated marker"
My question is can someone explain to me how it works.....???????

Does the air push on the volosity spring, compressing it and when you press the trigger it releases the air
The thing is if I put the standard spring in which pushes the balls out at 320 fgs (should be 250 to 280) and add a regulator.Will I be able to drop the air pressure, which will drop the Fgs and save air in my tank,giving me more tank time

OR am I looking at it totally wrong

Thanks for any info (from a newbie)

 

[M600]

http://www.deadlywind.com/paintball-animation/spyder-animation.gif

this is how a blowback marker works
adding a regulator will allow you to increase/decrease the pressure which builds up in the valve hence allowing you to control the velocity
you can also change the velocity by adjusting the spring

 

[d rabe]

change the spring will bring the velocity down on your rap 4 .If you can find one that achieves this!..The Marker was designed to fire at the higher fps ..

 

[SabreWolf]

most blow backs have a dialer in them which u adjust with an allen key down the back of the marker
I could be wrong on this though, been awhile since i used or owned one.