High cap mags with a wheel on the bottom use a coil type spring, there is an anti-reversal spring that will slip when there is too much tension, it's not really possible to overwind them. However a bit of oil on the wheel will make the latch slip easier. I took my M4 Hi-cap apart and had one hell of a time getting the coil sping back on so be careful opening it for the first time.
You can re-bend the anti reversal spring to re-enforce it and wipe away any oil on the wheel and AV spring.
A little oil in the BB line-up can go a long way too. I've seen my BB's jam in the mag but apply is extremely sparringly there so you aren't getting oil into your hopup chamber.