Good build, but: minigun has good basic stun, so I prefer T3C for even better crowd clear. Also, minigun has bad basic spinup time, so I choose T4B always. Here... +15% DMG means +1 damage per shot. With 9 damage you kill grunt with 6 headshots and with 10 damage you kill grunt with... yea, 6 headshots. As long as main usage of this build is killing grunts, T4A is nearly useless. Also, you kill naedocytes and swarmers with 2 shots anyway, so even for killing swarmers T4A is useless.

Also, shield is not "XXX". It's 22X. 221 for biggest area and 223 for longest duration. And some that I think is important. Alternative secondaries: BRT7 with Lead Spray or Experimental Rounds and Coil Gun with Triple Tech Chamber. Less Spray would be best choice for killing praetorians and oppressors, as long as Experimental Rounds is best BRT7 build ever. Universal single target that kills grunt with 3 bullets and that have very good accuracy (nearly as Elephant R). So I'd choose BRT7 with ER.