The guns primary purpose is killing humans and not hunting or target shooting. it would not have been invented in the first place were this not so and niether would the aforementioned ICBMThe would believe that a gun is what they were told it was. Many would think it was a toy. You don't seem to understand that guns have several purposes.
And I'm sure you can slice watermelons with a sword too but that doesn't make it cutlery . My original statement standsName another purpose for a lawnmower. If you can, then it is a tool with several purposes. If you cannot, then it's intent is part of the design.