Hi guys. My old Glocks just say the caliber on the top rear of the barrel...but noticed my 2013 G21SF to not only have the caliber, but also "AT", the polygonal symbol and another weird mark-I can't really explain. So what gives?
"AT" indicates that the barrel was made in Austria. I've never seen any "weird mark" so I don't know what you mean. In recent years typically there is a caliber indication followed by the dot-polygon on top left, and the Glock trade mark followed by AT on top left.
There is a chrysler emblem on my 43 I'm currently carrying. lol It also says 'Glock'. I've seen some that have the state of Georgia on it as well (I'm sure there are more.) They change quite frequently.
