I'm pretty sure I've seen plate carrier style harnesses that can be loaded up with iron 45's.

Found it: https://www.roguefitness.com/outdoorsman-atlas-trainer

This is what you're looking for, you need something purpose built, most bags aren't meant to be yanked around at those loads.

Only other thing would be the go-ruck rucking style bags with other handles and whatnot.