I got the gun used as a 17 MachIV. I figured it would be the perfect time to try the 17/23 SMc. I sent it out to Mic and he re-chambered it for me, he has die sets also. It's a HUGE improvement over the 17FB, which is no slouch at all....my experience has been less powder fouling, more performance and less case work( trimming etc).
The little extra capacity and the updated shoulder allow you to push a 25gr bullet a little faster than a 17FB can push a 20gr'er. The 25's in the 17 cal have much better BC and hit with more authority, IMO.
I think that's what I will do with one of the barrels from the group buy. Build a heavy bench model to fit between my 17VHA and the 5/35. John at H-G was looking to get some SMc reamers. Not sure if he has then yet, but would be worth a call. Few guys here might go in on one, PTG has the prints....keep my advised.
" It is hard to imagine a more stupid or more dangerous way of making decisions than putting those decisions in the hands of people who pay no price for being wrong. "