OW corerules p.68
Favoured weapons: Member's of this regiment gain +10 on all logistic roll's to obtain these weapons and ammunition for them.
and before any PC rushes to shout he wants meltagun, it should be pointed that these are only available, and this is my interpretation, for heavy gunner and weapon specialist.
also if there's anyother regiment in the battlefield who has the same favoured weapon these rolls get +20 also. As pointed in OW corerules p.163.
so OP should get from +10-30 in logistic rolls to obtain ammo for his weapon. Off course battlefield conditions are fluid and Departmento Munitorium could make one decimal error and send paint solvent instead of Heavy Bolter shells to said warfront.
But it's always in GM's control what can and can't be got. But if you chose HB it's pretty petty of GM to denie you from getting ammo for it. He should at least make some available as mission assainment gear or make other heavy weapon available for you to take. I have used that few times and if player's have rolled badly I have made at least 2 reloads available.
Well one time they had to make with only one clip but then they had bad drop and most of their stuff was destroyed or lost. Player was happy that he had the foresight to take his Standard Kit Lasgun with him.
Muutokselle annamme Elämän, Elämälle annamme Muutoksen.