First off, lets look at a signum. A signum allows for the model bearing it, to choose one model in his squad to fire at a ballistic skill of 5 for the rest of the turn. Now the arguement has been whether or not a model being given BS5 for the round superseeds snap fire as being BS1.
Lets read snap fire, now assuming that the shooter is now BS5 for this current round.
If a model is forced to make snap shots rather than shoot normally, then its ballistic skill is counted as being 1 for teh purpose of those shots.
This makes it very clear, that it doesnt matter what Ballistic skill you gave a model, if it is going to fire snap shots, its at ballistic skill 1. You are not shooting normally if you are making a snap shot.
Now lets look at something else regarding snap shots. Everyone has been trying to figure out how to hit flyers.
#1 If it uses a template or ordnance, or blast it cannot hit a flyer
#2 If it does not use a Ballistic Skill, it cannot hit a flyer.... Blood Lance is out guys.....
Since you cannot hit flyers in close combat, if it uses a WS it cannot hit the flyer.
Check this one out though....... A Mawloc enters the board undernearth a flyer? Is it hit? and how is this resolved? I will leave this one to you guys to figure out, and then I will give my answer later in the comments.
Page 13 discusses Snap Shots
Page 80-81 is flyers