Well, I was gonna stay away from "re-temper them" comments, but......
How do you know how to re-termper them if you don't know what kind of metal you are working with?
Different metals require different temps.
Joemolf....What kind of chisels you need depends kinda on your technique. All of this is hearsay, so take it with some salt; Some people use veiners to outline their work, some use gouges. Those that use gouges will probably need a larger selection of sweeps to cover all of the possible curvatures. Seems to me, the shallower sweeps could tend to be a bit wider than the deeper sweeps with the exception of a narrow #3 to get in to tighter spots of relief.
Maybe if I give you some 'misinformation", an experienced carver will correct. So, in that vein, I hear that a shallow sweep, #3, is good for removing background wood. I would assume both narrow(4mm or so) and some wider.
At least a couple of good straight chisels, I think they are referred to as #1. A skew chisel or two could be handy I would think.
Again, I AM NOT EXPERIENCED AT GUN STOCK CARVING, so please don't go buy chisels on my word/thoughts.
Hopefully someone more experienced, as in doing it for profit, can chime in and correct my mistakes.