Can someone tell me how to get this cylinder out? As you can see there’s a tapered pin and it goes through the frame so that the top sits flush with the frame. Then the cylinder is underneath the frame with a nut on the bottom. There’s no way to hold the pin from spinning? Early 70s case loader
Do you have an impact wrench, it might be fast enough to spin the nut off. I wonder if hitting the pin down the same time you turn the wrench might hold the pin. If none of this works a couple other idea's that might work. Center punch the edges of the pin in 2 or more places so it grips the edge of the bore it goes in, could you grind a slot in the pin for a big screw driver? If none of that works weld a bar or even a nut on the pin to hold it. You would probably want to replace the pin if you have to modify it to remove the nut.
Those nuts usually just come right off with an impact gun.
Had one once that was used in fertilizer. I didn't want to ruin the pin so I welded a piece of scrap to the head end. That way when it tried to turn it just wedged up and locked.
Maybe drill and bottom tap a hole (1/4”) between the pin and the bore body put in a set screw.
If its a tapered pin it should be wedged into the frame like a tie rod or ball joint. Shouldn't need to worry about holding it. If for some reason its loose in the bore and nut is seized I'd just weld a handle to the top side to hold it and zip the nut off.