Speaking as someone that's worked behind the counter at a gunshop before, I'd REALLY prefer that you'd carry it in unloaded in a case, box, bag, .... and before you start pulling it out, TELL ME what is going on. (Like, "Hey, I've got a XYZ pistol I need somebody to look at for a repair.") Yes, I work around guns all day. BUT, that doesn't mean I want complete strangers pulling a gun in front of me for no apparent reason. (I, for one, get the urge to pull MY gun what folks start drawing theirs for no apparent reason.) Carrying it in a box, case rug, grocery sack (don't laugh, I've seen it done), wrapped up in a blanket (seen that one, too) or whatever and TELLING THE GUY BEHIND THE COUNTER WHAT'S GOING ON before starting to pull it out is the best way to handle it.