Anyone have one. Any idea what kind of pressures it can handle? TIA.

www.handloader.com has a very good article on the Model 25-5 - it is listed on the home page. Look at the "all articles" and you will find other useful info about the .45 Colt in S&W revolvers- or were you referring to the Model 25 in .45 ACP?

www.sixguns.com has a bunch of good articles on the .45 Colt and/or the Model 25.

HTH

I have a 25-5 and 25-2. I use standard loads in both 850 to 900 fps with 230 grain in the 25-2. In the 25-5 250 grainers to 900 fps. Because the N Frame revolver was origionally designed for the .357 mag in the 1930's and the fact that the lockup cuts are under the hole in the cylinder as opposed to between the holes on some other makes (like the blackhawk, I'm not loading mine hot. I suppose you could load it hotter, but not to the point of the blackhawk loads.
Besides, the value on the older Smith and Wessons keeps going up and up ----- there is no reason to abuse them!
If you want 44 power--buy a 44!

I am not sure about the model but I saw a guy crack the cylinder on a military 45acp revolver he was shooting new factory ammo in. This revolver was parkerized and looked really sharp. I could feel his disappointment when the gun he had just acquired turned into an expensive piece of junk.

In a Handloader srticle on the .45 Colt, Brian Pearce opined that, since the 25-2 has been approved for use with 45 ACP +P ammo, one could safely load the .45 Colt version to the same pressures.

I think, but am not sure, that the 45 ACP +P is limited to about 21,000 psi.