"For
each result of a 1 rolled on its to hit rolls, the firing model suffers a wound (normal saves apply)."
P. 31 of the Rulebook
The thing that I do think is up for interpretation is whether for, say, a plasma gun totting marine, he does get to take armour saves after his weapon gets hot. The way I see it, he is taking a wound from a S7 AP2 weapon and as result is turned to slag on a roll of 1. It could also be read that he simply suffers a wound and can take his best save... This way of playing kinda sucks tho, as one of your guys is essentially carrying a suicide gun