I'm going to be the one to say it, there isn't much difference between a 10mm and a .40. Take note that I reload and have loaded for the 10mm and .40 for quite a while and I don't see what the 10mm truly offers over the .40, it's just more expensive. I have nothing against the 10mm at all, but it's not what most make it out to be. People buy a 10mm for velocity, the problem is that they don't know when to quit and push bullets too fast, which is bad.
From similar barrel lengths the 10mm has a 100-150 fps advantage, and I'm talking about a warm loaded 10mm vs. a warm loaded .40. The issue is that both the .40 and 10mm can push .400" JHP bullets fast enough to reach the point of bullet failure, which hurts penetration and that's what you need when hunting.
For instance, using Longshot powder in the 10mm and .40, I can get a 180gr JHP @ 1250+ fps from a Glock 20 10mm. From a Glock 35 .40 I can get a 180gr JHP @ 1250+ fps also, but have a lighter gun with a longer sight radius and still have 15+1 capacity. The extra 100-150 fps the 10mm gives isn't even going to be noticed, especially when the velocities are at levels that surpass what the particular bullet is designed for. Moral? Faster doesn't mean better, especially when the result is less penetration and bullet failure.
You're better off buying a .44 Mag, for example. Instead of pushing the exact same bullet 100-150 faster, you get a bigger bullet, a heavier bullet and faster velocity at the same time. If it can't be killed with a .40, don't count on the 10mm killing it either, you would be much better off with a big bore revolver.
Glocks and Single Actions