This is based in part on my other favorite Omnimech, the Savage Coyote Prime; without Advanced Tactical Missile launchers, however, one must improvise. The alternate version swaps the SSRM6's for SRM6+A's, another half ton of ammo, and an extra heat sink. I've been playing around with one that uses an LB-20 or a UAC/20 in the ballistics arm and having a lot of fun but the whole thing is pretty short range; dropping it down to the LB-10 and adding the PPC lets me at least poke at people as I advance and encourages them to keep their heads down.
