Measure the barrel/cylinder gap.
I’ll dig out the feeler gauge in the shop tomorrow but for now I cut a small strip of paper and placed it between the forcing cone and cylinder. I closed the cylinder and the paper would slide back and forth then I opened the cylinder and rotated to the next chamber, closed the cylinder and the paper slid back and forth, repeated the process for the other 4 cylinders and there is one cylinder that the paper won’t slide easily. You have grip the paper tightly to pull it out.
