.410?
That gun looks like a Browning Citori XS Skeet so it is more likely a 20 gauge.
For the photo-Op they probably pulled the shot from a shell and let him shoot just the wad so he wouldn't get a bruise.
It looks as if he was coached by someone who didn't know any more about skeet shooting than Obama himself.
Or the coach was someone who was happy to let the photo show what a pretender Obama really is.
Notice how high the buttstock is against his shoulder, only part of it is pressed against his shoulder. That could hurt if there was any recoil to speak of. Somethin’ ain’t right.