I also think the tool on the right is an AR ejector retaining pin R&R tool. The carefully specific OD turned on the end of the threads is a tell-tale. It should fit into the head-stamp recess of an AR bolt with little slop. If there is an off-center hole in the web of the 'fork' that the threaded part is pointed at, and the flash glare obscures this but it looks to be the case, then this would be confirmed. That hole is clearance for the retaining pin when being driven out.
Based on the relative sizes of the tools I think it is too big of a bore for a 1911 barrel. The bore for a 1911 barrel would be closer in ID to the OD of the threads of the Ejector tool. The shape of the ID is not right for holding an AR upper, but it looks to be barrel related though I don't know how or for what purpose.