'But don't take my word'
LOL
No problem
Cunningham testified to this about ejecting the shells:
Mr. EISENBERG. Now, Mr. Cunningham, would you show how you would eject the five expended shells?
Mr. CUNNINGHAM. yes. These are very difficult, by the way, to extract, due to the fact that the chamber has been rechambered. And as you can see, you get on your cartridge cases a little ballooning with these smaller diameter cases in the .38 Special.
"Difficult .... to extract" due to a "balloning" of the shells. Oswald used "undersized" bullets that expanded or "ballooned" upon firing. They would then "stick" and he would have to shake them out. Witnesses saw him shaking the revolver to remove them.
Those shells that stuck were of two types and were the same type of bullets founds on Oswald when he was arrested.
And ballistic tests done on the revolver using this smaller ammunition showed this to happen.
Here is Cunningham's full testimony:
http://mcadams.posc.mu.edu/russ/testimony/cunningham1.htm