For beginners and those who need a refresher on airsoft springs, here is Shreq Airsoft with a comprehensive guide... "The M rating on your airsoft spring is NOT what you think it is — and your cylinder, FPS rings, and airbrake pins are changing it every time. Here's the full breakdown.

In this airsoft spring guide, I cover everything you need to know: what the M rating actually measures, what changes it inside your specific gun, how to select the right spring for your setup, and how to figure out what spring you're running if you've forgotten."