Are return springs worth getting as well? Pro/con of a return spring? Return springs are normally only useful if you plan on doing a lot of running, or you hold your front reg after you pump to get a more stable platform. The ccm kits are renowned for being very smooth, and with the right internals, you can accidentally pump your marker while you're running (as the arm moves backwards and forwards), if your marker pumps itself while you're running, you might feed two or more balls into the breech by accident.
A return spring prevents the arm from moving while you run, and returns the arm to the original position (cocked)
Only real con of a return spring is that you work against the spring to **** the marker, but it doesn't make that much difference. If i were you, i'd get a pump kit, play with it a bit and if you think a return spring would be handy, measure one of the guide rods on your pump kit and go down to your local DIY shop to get a suitably sized and weighted spring. CCM return springs are just springs.
I'm assuming these'll work with a hinge-trigger (stock 05 Prostock)?You assume right
Will these kits allow slamfiring?
The sniper (pump kitted autococker) platform does not traditionally allow slamfire. Due to the nature of the internals, you must release the trigger before the marker can **** again.
CCM make an autotrigger pump kit (that's what slamfire is called in the sniper world) which has a cam mechanism for reactivating the trigger each time you pump.
The economy and deluxe kits do not have this feature, they are simply a pump kit.