I have a model 97 coming soon and am loading up test loads for it.I have a bunch of 125 xtp bullets and am wondering if they are hard on forcing cone/top strap(on the 97) like on a Smith model 66.
Not sure about the 125, but I ran some Winchester White Box 110gr .257 through my 97 and noticed some top strap erosion. This likely has something to do with powder choice too though (one belief is that ball powders may have more of a sand-blasting affect than flake powders). I'm not sure if the erosion I'm seeing was a result of the 110's alone, but after that I decided to stick with heavier lead bullets and avoid the 110 and 125. After seeing the results with 158 gr LSWC, and Unique, I'm happy enough that I have no reason to try anything else right now (for my applications.. which is pretty much just target/plink), and I feel better believing that the slower, heavier bullet will result in less wear to the top strap and forcing code. Disclaimer: I don't have a whole lof of evidence to back this up. It's just based on what I've read and what I've seen on my own 97 with relatively low round count.
If you do go the 125 gr route, just keep a close eye on condition of the parts, even to the point of taking pics (under magnification) of those areas before/after. Supposedly erosion can occur even after only a handful of rounds - it doesn't necessarily take hundreds.