Batman -
Note - pressure is...pressure. As the pressure climbs, it will ALWAYS be more difficult to continue pumping more pressure into the cylinder, no matter the gun.
As for one person say one gun is easier than another...again, pressure is pressure, all the same. Beside, a person weighing 250lbs, vs a person weighing 125lbs,...which one do you think will have less problem pumping that last 30 strokes ?
Mike