Goblin generals don't distinguish between troops and ammunition.

Barrage of Expendables

{R}, Sacrifice a creature: This enchantment deals 1 damage to any target.

Jumpstart

Magic 2014

{R}, Sacrifice a creature: Barrage of Expendables deals 1 damage to target creature or player.

Barrage of Expendables deals the damage, not the sacrificed creature. Notably, that creature having deathtouch or lifelink provides no additional benefit.

Because targets are chosen before costs are paid, it is possible to choose a creature as the target of the ability and then sacrifice that creature. The ability won't resolve when it tries to resolve and no damage will be dealt.