On the few comments suggesting the 10mm is either too much recoil or too expensive to plink with, here's my experience:
1. Recoil. when I first got my S&W 610 I took my (very petite) gf and her 16 yo daughter to the range. They put 200 rounds though it and only stopped 'cause I ran out of ammo! Neither has much shooting experience. They certainly didn't find the recoil objectionable, nor do I.
2. Cost to shoot: Bulk ammo from (for example) Georgia Arms is $170 per 500 (plus shipping) v. $135 for 40 S&W. IMO that's not enough of a difference to influence caliber selection and while the 40 S&W is a solid self defense round, the 10mm is amazing. In fact, at that first range session the 10mm became a contender for my favorite round; the other being the 45 Colt (hey, I'm a wheel gun guy!) Though mine takes both rounds I shoot mostly the 10mm because I enjoy the feel of a more robust round. That said, the suggestion to buy a 40 S&W barrel is a good one; but it will take almost 3,000 rounds to pay for it. On the other hand, you'll then have a fine multi-caliber on your hands and I like multi-cals (part of my original attraction to the 610).