Or you can try make rounds that wont go off when hit by Heat rounds. Kinda hard when they use combustible casing.To be fair, unexpectedly few of them cooked off in combat.
Most kabooms were burned down later on - and in this case it doesn't matter, burned down equipment is unrecoverable regardless of its looks.
You can do it just fine, there were multiple projects and prototypes.
No one did this in the end because there was already one working just fine, not because it was undoable.