For a working axe, the bevel should be about 45 degrees. For a throwing axe, it works better with a 30 degree, or even thinner bevel. However, be careful to not hit knots, or stales, or nail as the thinner bevels will not support the edge well enough to keep it from chipping out.
I use a double bevel approach to sharpening my throwing axe. It has a 30 degree aproach bevel, and then I raise it up to put a fine edge on the very end of the axe. Probably about 45 degrees. This is done with a fine arkansas stone, after which I strop the edge on a leather belt. When I spend the time, you can shave with that edge. However, I am only interested in getting it to stick well in the wooden target butts. BTW, a straight razor will have an " Approach " bevel of about 22 degrees. A splitting wedge should have a 90 degree bevel. A working axe- as in two hand axe, should have a 60 degree bevel. The smaller hand axe used to cut sticks and firetools works best with a 45 degree bevel. If you have one of those hammer wedges- looks like a splitting wedge, only narrower, and has a long handle on it like a pick axes, it should be used with a 60 degree bevel, too, even if its being used to split stumps. The reason for the wider degree edge on the splitting wedges is that they are normally held against a log, and then hit with a sledge hammer. If you do that kind of thing with a smaller angle, you are likely to chip the edges. It has to do with steel hitting steel with the onther end being dampened from vibrating by the log or stump. Splitting wedges are also used after a split is already created, to widen the crack, and walk the split down the length of the log. It is truly an inclined plane being used for that primary purpose, and not as a substitute for an axe or knife edge. To use a splitting wedge properly, you set it in line with either the growth rings, or with the radial fractures.
The reason you need the finer angle on the bevel of a throwing hawk is that you can't be that precise, and you are more likely to be driving the edge into cross grain. Most of the current throwing axes are soft enough to be filed, and you are more likely to gain good control using a file, than using a powder grinder. It will take you some sweat and time to file the bevels to the proper angles, but once done, they last for years. Good throwers touch up the edges on their axes before every practice, and every competition. Some keep a honing stone( Black Arkansas) with them at the line, to hone away any nicks in the blades.