I picked up some ball lock kegs from a person who was getting out of the hobby, on one (or more) of the kegs, there is a strange sized post. The post is 5/16ths and the ridge where the balls drop into is a bit bigger. I pushed on the gas connector and it stuck like a fish hook. It took me 15 minutes to pry the connector off.
Of the three that I was working with, this is the only connector that I found to have this problem. All the other ones were the standard 7/8 hex and star type.
Anyone run into one of these dandies before?