I carry a NAA .22 Magnum for those times when something bigger just isn't possible or practical. I use Winchester's 30 grain V-Max which has a published velocity of 2250 fps (I am sure that it doesn't reach that velocity when fired from my NAA). In a purely subjective test, I shot an over-ripe watermelon from about 10 feet away and it literally exploded.

If you get a chance to test some, I'd really be interested.

I also bought some Hornady 30 grain V-Max (2200 fps) at a really good price at last weekend's gun show (about half of what I paid for the Winchester at a local gun shop). I didn't have another melon, so I used a couple empty 2 liter soda bottles filled with water, again at about 10 feet from the muzzle. I expected to see the bottles rupture and spray, but both were through and through shots. The exit holes on both bottles had less than 2 inch tears and the caps, which normally blow off, stayed on the entire time. I was able to find one of the bullets in the backstop, and it did not expand at all, in fact, the red polymer tip was barely deformed and hadn't compressed into the hollow cavity at all.