Originally Posted by armorer951

Probably peening on the cutaway at the top of the body of the bushing that accomodates the crosspin. (securing the bushing) If the movement is very slight it's not a problem. If the bushing protrudes past the breechface surface too far it could interfere with cylinder rotation, by catching on the case rim, or interfering with proper headspace. I would keep an eye on it for sure. Is this your carry gun?