I have used the 140 xtp in a 38 snub nose and a 6" magnum and get good groups out of both revolvers.
I have used reddot,greendot,unique,bluedot,w231,800x,SR4756,Universal clays and imr 4227.
4.4grs of reddot worked well in both and in the Magnum 13grs of imr 4227 gave groups under an inch at 25 yards but it
worked with most powders when you hit the sweet spot.
For some reason, this weight bullet and style shoots well in all my 38 and magnums with the medium loads.
I did get it up to 897 fps in the snub nose but 836fps is a lot easier on the J frame and 1250 fps in the mag is a very nice
target load that prints near an inch.
Less wear and tear on the revolvers also, since it does not have to jump to the barrel from the cylinder,like the 110 and 125gr Jhp bullets,have to.
Enjoy.