Well,for one, it didn't shoot snowballs; it sprayed gas. The one my sister used hadn't been modded at all, and the OP says nothing about having to mod it to pull off these one-shot kills. All we know is that we tried it against the Deathclaw in Concord, and it was actually significantly worse than the Minigun they give you because it was a continuous damage weapon with a horrible magazine size. It's damage stat is actually listed as 20, and with a magazine size of 20, that's only about 400 damage per reload. A full magazine barely dented the Concord Deathclaw's health.