WARNING: The screenshots in this film sadly spoil the incredible ending. If you do not wish to spoil the ending for yourself, please watch the movie before viewing this page.
As the townspeople hole up in the grocery store they discover something bad is out in the mist. In search of weaponry, one of the women in the group reveals a sidearm she keeps in her purse. This sidearm is a Colt Magnum Carry, the stainless reproduction of the Colt Detective Special chambered in .357 Magnum. Unfortunately for the group, she only carries two speed loaders for it. In search of someone with enough experiance to use the gun, Ollie Weeks (Toby Jones) steps up, claiming he was a competition shooter in the '80s. The gun is used several more times before Ollie is killed by a creature in the mist as he follows the group of lasting protagonists out to the car in an attempt to escape. The gun falls into the hands of David Dreyton (Thomas Jane), now only loaded with four bullets. The group of five drives their car out as far as possible before running out of gas. To spare the group the deaths awaiting them out in the mist, David offers to kill them with the gun and figure something out for himself. He then kills everyone in the car and steps outside so the creatures of the mist can take him, only for the U.S. Military to arrive and rescue him.
One of the U.S. Military personel's M4A1 is fitted with an M203 grenade launcher. It could also be a Cobray 37mm launcher but it isn't seen close enough to be sure.
It's a self-propelled gun of some type. Since these are U.S. soldiers, I believe it's supposed to be an M109 Paladin, but the vehicle has some obvious visual differences from an M109. I think it might be a British FV433 "Abbot", which is a similar vehicle. Cloverfield also features an FV433 standing in for the M109, as I explained on the page for that movie.
