I’m a Mak noob and was wondering why I see so many people changing the factory recoil spring to something heavier. I’ve always thought the Russians had a pretty good handle on how to build a reliable, robust gun and that would include knowing what weight spring to use in a blow back pistol. If the Russians thought that 17 pounds was adequate, why change? Particularly since it appears that the majority of the available ammo is somewhat less powerful then that for which the pistol was originally designed.