I am using the factory recoil springs, both before and after extensive CGW mods. I need to replace the stock outer recoil spring every 600 rounds or so, because it starts to misfeed occasionally. Each time, after the outer recoil spring replacement, the misfeeds stop occurring. People generally:
1. Increase the recoil spring power if they consistently use high power ammo, or
2. just replace the factory recoil spring if the cartridge ejection distance become excessive (greater than perhaps 10-12 feet), indicating a weak spring.
Otherwise, no need to increase the recoil spring weight. IMHO
--Tom