A loadout that served me well in the caves last night

Admittedly this does draw from multiple different warbonds, but:

• Plasma punisher, to force burrowers to the surface, stagger them, get through medium armor, and deal aoe damage. Slow TTK but I've always preferred it on the bot front to stunlock devastators and go trooper/commissar bowling but leaned towards incendiary shotguns or an upgraded carbine for bugs previously.
• Verdict, medium pen sidearm, accurate at subterranean engagement ranges (especially on things that want to eat your face), hits hard and fast.
• Pyrotech grenades, aoe, high carry capacity, lock down a breach / burn everything in one corner of the cave / coming through a tunnel.
• Gunslinger armor, I was using medium, but can see an argument for heavy.

Strategems could vary, but I went with either a HMG or a GL depending on what the other teammates were bringing, supply pack or gas watchdog, a commando, and a 120mm barrage. Supply pack speaks for itself, the gas dog repeatedly moved ahead into a cave and gassed everything in it before they swarmed me. The 120 has enough coverage to take care of a breach or up to a medium nest on the surface, and is tightly focused enough to fit at least some of the barrage down into most of the objective skylights in the tunnel system. Commando was used like an EAT, call down when something big comes up at a skylight fight, or if there's a shrieker nest etc on the surface, then grab the GL or HMG again. I returned to that habit on the recent return to Hellmire when finding MG43s on the ground frequently. I've always preferred the Commando to EATs because of a) laser targeting, b) snap-fire ability, you don't have to wait to extend the tube like you do on an EAT, and c) ability to spread the damage around if needed. (Ex: two rockets will drop a charger, or even a titan if you get it in the face)

Speaking of HMGs, Engineering Kit (-recoil when crouching, +grenades) could be an option with the HMG too, but I find the HMG's recoil manageable if crouched/prone and ADS so was leaning towards gunslinger to keep the verdict firing, like the gif / movie clip of a guy going down a hole with a 1911 and old right-angle flashlight.

(And speaking of flashlights, having the minimap open gives you a small amount of local illumination. I need to pay more attention to if the plasma punisher projectiles were illuminating tunnels, they didn't help much on the super dark rainy megacity maps a few MOs ago but that might have been map-specific.)

And if you haven't experimented with changing the RPM on the MG's, do it! Some people like slower fire, I prefer max RPM on all 3, Stalwart / MG43 / HMG.