My next project was to get this single shot working I figured out the problem with it after shooting it. The cases are expanding in the rifle and get stuck. Does anyone have experience with a marlin model 100m or a jc higgins 22 103.18.
Casing on the left is a normal spent casing
Right is out of the gun I am working on

At first I thought new barrel. Then remembered the rifle your talking about. There is a square shape that holds the bolt forward when you close it. If the bolt can wiggle a bit when its closed that is where the problem is. Probably wear on the receiver. Might be on the bolt. Its possible the bolt might be a replacement.

that looks like brass of an out of battery firing.
which would be odd for a bolt action
I am almost wondering if maybe you ended up with the wrong bolt at some point

if you take a cleaning rod and bolt closed run it down the barrel mark it with a piece of tape that is bolt closed , then open the bolt and see if it is protruding back past the breech face when at the tape mark it shouldn't be any more than the rim thickness

I assume you checked no barrel obstructions and it doesn't look like the barrel walked forward and that the barrel retaining pin is in place.