I'm by no means an expert but I'm a good guesser, the top is one is a muzzleloader my girlfriends dad works on roads, bridges...etc. He's found a few barrels like that before, he does a lot of digging. I'm guessing here but the bottom one looks to me like a remington rolling block receiver, looks like some of the parts have broken off of the receiver.
But like I said I'm guessing...
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