[fastmonkey87]

I think the bolt is for a sub cal 50bmg recoilless rifle but I need expert ID for both pieces please. For reference I put a 50 shell in it. Also a rough value on them would be appreciated

 

[Belt-fed101]

STATE ARMS COMPETITOR 50 BMG BENCHREST SINGLE SHOT BOLT , but I'm no expert. Just making guess, when i was i market for 50cal single shot remembered seeing one that looks like that

 

[fjruple]

The other part is a firing pin tip to probably a Remington built 1903A3