I am new to the 10mm world, but have been trying to read more about them. I have been shooting mild stock ammo and some moderate reloads. I want to purchase some hotter stuff like Underwood Ammo or Double Tap has to offer. Something like a 180 grain bullet traveling around 1300 FPS. Should I order a heavier recoil spring and if so, go with the 20 lb. or 22 lb.? Wanna kill these ads? We can help!