In my experience none of the XTP bullets expand at 38 velocities even loaded to +p levels. If you're a hand loader you might be able to get somewhere with the 110 grain XTP with a max +p load of Power Pistol. From what I've seen the XTPs are really designed more for 357 magnum.
There are a few 38 loads I'd reccomend, I'll start by saying I put penetration above expansion. Expansion does no good if the bullet won't go deep enough to hit something vital. For standard pressure 38 I'd go with a solid bullet, I like the SWC myself but a lot of guys like full wadcutters. For +p loads I like the Federal version of the FBI load, the Remington version is very good too but I prefer the Federal myself. The Winchester 125 grain SJHP is another favorite, Remingtons version is good too but again the Remington would be my second pick. The 125 grain Remington Golden Saber is a very good but I prefer a little more penetration myself, same with the Gold Dot Short Barrel. Both are very good loads but they're not my first picks, I just prefer to be closer to the 18 inch maximum rather than the 12 inch minimum. The Federal FBI load and the Winchester 125 SJHP are my 2 top choices.