Even if they couldn't do it so you pick on individual Ac base, but had a "Artemis / Standard guidance" option to the side that changed all the Ac on a mech to a type of ammo I believe it would still find good use.
As things are and much like in the TT Ac's are something you put on if you have weight but not the space to equip so many heatsinks to go pure laser/ppc , that is until you get to special ammo.
The 2 types of special ammo that seem useful in MWO could be the armor piercing ammo ( would still do most damage to armor but some to structure with a chance to crit components ) and precision ammo that would translate to less ballistic drop off and higher projectile speed.
All special ammo have the same drawback and that is lower round count as a balancing factor, also they could play with effective range and heat if need be.
With such a high heat cap we have now and the ability to mount ~20+ DHS lasers are the optimal choice as you can easily go over the 30~35 pin point alpha of old so there is little space, with all them DHS, for a slow traveling, limited ranged, ammo dependent ballistic weapon ( unless boated ). This addition could breathe new life in to Ac usage with more flexibility.
Edited by Nik Reaper, 27 September 2015 - 07:58 PM.