Squirt gun
Imagine the apocalypse occurring however you like: zombies, flooding, meteor impact, gamma burst, nuclear war, or all of the above. Modern manufacturing and machining of weapons is impossible from this point onward.
Assuming this much what, in your opinion, is likely to be the last functional pre-apocalypse firearm?
??? Cartridge has oxidizer in the powder... it will fire in a vacuum.I wont need any guns because I will be the only living thing around...so what am I gonna shoot at?
Once the nukes consume all the oxygen...a gun will be useless since it wont fire without oxygen anyway.