A standard modification among the Nerfing community for any spring-powered gun is to simply stretch the spring. The formula for the force exerted by a spring is Fs = -kx, where ‘k’ is a spring constant (which varies from spring to spring) and ‘x’ is the difference in length between the spring at rest and the spring when compressed. By stretching the spring, we will increase the value of ‘x’ and therefore increase the force exerted by the spring. So, for instance, say we have a spring which was originally about 20 centimeters long uncompressed, and about 5 centimeters long compressed. By stretching the spring another five centimeters, we effectively increase the force exerted by the spring from 15 times the spring constant to 20 times the spring constant. That’s a 33% increase in force! –The Physics of Nerf (NerfOnline.com)
I seem to remember being sent this link before, but I didn’t blog it. Via Metafilter.