Two comments, Nero:
First, a 640 will comfortably handle +p ammo from here to eternity; if your concern is the gun, you needn't be concerned.
Second: assuming your concern is something other than the gun, and assuming your 640 is a two-inch gun, it can be virtually guaranteed based on numerous independent tests that the hollowpoints listed here will not expand, but will plug up and create a relatively narrow wound--an innefficient wound.
For that reason, I would firmly concur with tbeb above, that the best standard pressure load for a short-barreled 38 is the 158 gr. SWC. The lead bullet will get a higher velocity per mass than any jacketed bullet; and the flat nose will transmit the load's limited energy better than a relatively rounded (and non-expanding) JHP.