Some people just like Lurms. And as
@TFT-A9 said, you can load some pretty nice ammo into those.
Fill one bin with Thunder LRMs, chuck those at a chokepoint and give the other team the good news. Or use one of my favorite alternate ammo ever, the Semi-Guided Lurm. No penalty besides cost (and who's tracking that?) without a spotter, and with a TAG lock you get to ignore all target movement penalties, spotter movement penalties,
and the indirect fire penalty.
Sure, you don't need to mount it on an 80-ton 'Mech, but look on the bright side: anyone getting within minimum range of the LRMs still has at least one Large Laser (depending on the model) and a 8-point
battlefist to deal with, plus all that armor. That thing is no helpless support-fire 'Mech up close.