Good concept, but I feel like the dice assignment should have been more frequent. The fact that you roll the dice and assign them only at the very start kind of make you forget that it was a mechanic and that it was important.
Also, since the melee weapon is way too risky (for not much reward), the ranged weapon is the only weapon you can use if you want to survive for a long time. The problem with that is that assigning dice to the melee weapon's slots becomes useless. You could make the melee weapon more powerful to prevent that.