Quote Originally Posted by MDriskill View Post
Apologies in advance for pulling things out of my rusty memory instead of looking them up, but one way to think of it is that a springer uses a small volume of air at high pressure, where an MSP uses a larger volume of air at lower pressure. I vaguely recall reading "somewhere" that the pressure difference is an order of magnitude, like maybe 200 PSI stored in the pump gun's chamber, vs. 2000 PSI generated for an instant in a 12 FPE springer?

I grew up on "pump guns" and as much as I've come to prefer springers in my dotage - the light weight, variable power, fixed barrel, and recoil-free firing cycle of my ancient Benjamin "Tootsie Roll" 347 are still great. When I am asked by a "non airgun" friend to recommend one airgun for plinking or pesting, I most often steer them toward an MSP.
You might find this recent thread interesting.

http://www.airgunbbs.com/showthread.php?879722-Pumpers