Well, that'a a start for sure !
Here on ASC we have a nice spring chart :
http://www.airsoftcanada.com/SpringChart.php ... is it still reliable ?
By looking at it, I saw some similarities ... like the KA M110 and Systema M110 or the KM 120M and the Systema 120M having the same approx. velocity ... simple coincidence or puting a ''M'' with a number is a standardised code ?
Like...is the Modify S110 or the Mad Bull M110 similar to the Systema, KA or wathever M110 spring (thus shooting at around 389FPS) ?