...if they annoy you. But here's an example of what I'm thinking of.
If we pretend that this sketch of mine roughly represents your design, imagine what will happen if the two springs have equal force, but the left (master) piston is (even slightly) lighter than the right (slave) piston.
When the gun is fired, the master - because of its light weight - would accelerate forward faster than the slave, allowing the cable to go slack. But then, at piston bounce, that same light weight would cause it to stop sooner and then accelerate backward faster, extending the slack cable.
Under these - hypothetical but still plausible - conditions, what would happen if the cable suddenly goes (i.e., snaps violently) taut?