Lt Limpy, on 26 November 2012 - 02:59 PM, said:

Well, changing out the skeleton is off the shelf parts in exactly the same shape, but of lighter materials. It's a bolt in replacement.
Changing an energy mount to a ballistic hardpoint would require a different fire mechanism, different programming in the computers, different stiffining/recoil absorption, adding an entire new path to the pre-engineered feed system that can take ammo from any point on the mech and feed it to any ballistic hardpoint.
Going the other way would require lots of re-routing of high current energy busses.
Frankly, I don't think the mechs should be able to change much of anything. I'd be very happy if the mechs could only substitute smaller weapons of the same family into hardpoints. And at that, energy only, or A/C to A/C only, and absolutely, only down.
You aren't going to put a 120mm howitzer where a 20mm autocannon used to sit. Just ain't gonna happen.