Originally Posted by
tom12.7
The green spring has some more L1 tension compared to the Colt rifle action spring. This can benefit some, but not all. It is an available option. The green spring has more L2 tension compared to the Colt rifle action spring. Having extra tension in L2 will allow more energy to be available to function the forward action cycle for that portion of the stroke. The negative associated with the extra L2 tension is that the BCG will spend less time in total cycling rearward behind the cartridge case. With less time available, you can run into issues with the magazine having the capability to consistently present the case for optimal feeding.
It's not that adding a green spring to an A5 is terrible, its not. The baseline A5 adds a generous improvement in timing over a carbine system. With the A5H2 green spring combination, you can lose some of the timing gains in bolt over travel that you gained with the baseline. The higher mass A5 buffers can increase the timing benefits further, so as you increase mass, you increase time overall in the stroke. That can bring the bolt over travel time into a more comfortable time duration with a green spring.
This is provided that the porting supports a satisfactory cycle for the combination. When comparing the cycle of a standard A5 setup to another with different mass and spring loadings, more mass=lower bcg velocities, higher L1=more initial time delay to initiate the stroke and more forward velocity back into battery, higher L2=less time in bolt over travel with more stored energy to function that portion of the cycle. High velocities decrease timing for events, we are looking at distance over time.
The Tubb flat wire springs are a topic of their own, they can be beneficial in both carbine and rifle actions, but they can add quite a few secondary issues that normally would not be considered for this system with a normal Colt action spring.