Bullet hp 101:
Typically, the size and depth of the hp determines at what velocities it will function properly at. Larger hp's ='s slower velocities.
Same bullet mold just different hp pins. The penta points open extremely fast and are best in snub nosed revolvers/low velocity rounds.
Lyman made the popular "keith" bullet designed 173gr swc/358429 into a hp version. The 358439
They actually did 2 versions of this mold. The 358439 hp is a 158gr hp with a .125" diameter pin.
The 358429 hp version used a shallower hp hole with a .155" diameter hp pin.
As far as the cannalure goes more likely than not they are passing their 2nds out in their bulk bullets. What you really don't want to see is a cannalure on the left bullet in the picture RDub posted. It's a deep cannalure made for a heavy roll crimp. But A a minimum you want the seating depth of a bullet to be at least as deep as the bullet diameter. Hence, a .357" bullet has a minimum seating depth of .357". Anything less you don't get enough neck tension to hold the bullet in place.
When I make/swage my own jacketed hp's for the 38spl/357's I like to leave allot of bullet base before the cannalure. The deeper seated bullets have better neck tension and taking up more case capacity makes them more consistent/powder is less position sensitive.
Playing around making bullets with duel cannalures. I use the top cannalure for revolvers and the bottom cannalure for "Contender only" loads.
Those large deep hp's were designed to be at their best in the 1100fps range. Why 1100fps???
Because I found an extremely accurate load for the contender @100yds. That bullet/load combo slowed down to around 1100fps @100yds. I planned on using that bullet/load/hp combo in the 75yd to 125yd range so I made a hp bullet that had a hp design that is optimal for those yardages.
Anyway look at the design of a hp and make sure it fits your needs. The size/depth of a hp tells you what you need to know.