Does the damage stat for a two shot weapon include the damage from the extra projectile? I had thought it didn't, because when I looked at the stats for 'Big Boy' when deciding whether or not to buy it I'm pretty sure it was the same as a regular fat man, but then I got a two shot hunting rifle, and after fully upgrading it (including re-chambering for .50), it's doing something like twice the damage of any other .50 weapon I've picked up (around 150 for the two shot, possibly more; I can't remember this early in the morning exactly), so now I'm not sure.

Hm, it should show the damage including the second bullet i think. My two shot laserrifle damage indicates that too.

It shows the damage as I've compared a combat rifle and a two shot combat rifle with the same mods and the two shots damage is double the regular combat rifle.

https://www.reddit.com/r/fo4/comments/3tjngh/useful_info_inside_on_games_mechanics_after_a_lot/

This explains what exactly two-shot does for your weapon, along with some other useful info.