tripper wrote: "...I have settled on is the 140 speer btsp"
Could that perhaps be the Sierra GameKing? Speer does not make a 140 grain BTSP, though they do have a 145 grainer.
Two excellent bullets for the cartridge are -- sadly -- no longer made. The 130 grain Sierra Single Shot Pistol bullet and the original Hornady 120 grain SSP (#2811, not the later itpped #22811 version) performed splendidly. I also took a number of animals with the 120 grain Nosler BT, but a couple friends of mine have experienced not-so-good results with that bullet in the past year or so. (I have not shot recent lots so can't comment on that, but the 120 grain BTs I used in the past afforeded an excellent blend of expansion and penetration and almost always exited on a deer given broadside presentation.)
The bullet in question -- the Speer 115 grain HP -- is indeed wicked at Waters velocities and will give limited penetration while causing extensive damage. Given a through-the-ribs lung shot, it will do fine, but match it up against a shoulder bone and you're asking for trouble. It's not a viable choice for deer-sized game in my experience.