|
Generally, internals of newer CA M15s are quite good with the exception of the piston and piston head. They're known to be problematic. The hopup rubber is apparently quite poor too. Otherwise, the gears and motor are good and it already has metal bushings, so no need to upgrade those.
Based on the research I've done, I'd say if you're going to upgrade your spring, you should also upgrade the piston and piston head as well to prevent issues.
For my M15 rifle, I ordered a Systema polycarbonate piston, Systema silent piston & cylinder head sets. Shortly I'll be ordering a Prometheus MS110SP spring, airseal nozzle, and new hopup rubber. That should get me somewhere in the 380 FPS range and give me good range and accuracy. I may or may not get a tightbore barrel for it down the road.
That being said, my rifle has performed very well to date. I don't have access to a chronograph, but I know from the coke can test that the velocity you state is about right - 300 fps give or take 10. I can shoot into the coke can, but can't quite make it through the other side. Other than that, it's got a great ROF and it's really accurate at ranges even over 100 feet.
__________________
|