Have no explination for "Buffalo Bore" ammo being labeled "Double Tap". Kind of weird.
The Fed Hydro-Shok is the much talked about (snickered at) FBI load. I only generates 1030 fps from a 5" barrel. This is just a bit over 40 S&W performance and might even be matched by some 40 rounds from a 5" barrel.
I will concede the Double Tap rounds I've tried so far were not brilliantly accurate. The most accurate load I've shot to date has been the Hornady 180g XTP.
This is sort of a medium 10mm in terms of velocity. Not up to the original standard of performance but a good bit hotter than any 40 S&W with the same bullet weight. Hornady claims 1180 fps and my experience with them is they are one of the more honest in that regard. Occasionally I've chrono'd some of their loads and gotten a bit more than the factory says. Never had that happen with any other brand of factory ammo.
A good example of wishful thinking by the ammo makers is the 10 mm Winchester 175g Silvertip. They claim a velocity from a 5" barrel of 1290 fps. The last time I shot it through my Oehler SkyScreens I got 1167 fps from a G20. I talked to one guy who only got 1140. Never met or heard of anyone getting 1200, let alone the claimed 1290.