I recently gave in and purchased a .410 for turkey hunting. I hear a lot of talk and discussion on the subject and just could not resist any longer! Ha. I found a used but unfired Mossberg 500 Turkey at my favorite LGS. It has full coverage Mossy Oak Obsession camo, middle bead and front FO red bead, sling studs and a 26" fixed full choke barrel. I outfitted it with a Outdoor Connections Super Sling 2+ MO Obsession. I measured the bore at the end of the barrel and it measures .389. I think that is tighter than standard full choke. Am I right? I think it leans more to the extra full side. Yes? Unfortunately I don't have any factory TSS shot shells to try in it at this point and it may be a while before I do. Thank you for any info you fellows can provide. I have heard that .385 to .390 is in the right choke diameter range for TSS. Is that correct?