I took Warhorse and the Sig P229 with the .357Sig barrel I fitted to it. Both have recently had a version of a "short" trigger fitted, to help me do a better job of shooting. Here are some typical results:
My tendency to throw shots to the left has decreased somewhat with the shorter trigger reach. I still have to work at some bad habits, but I'm getting better results with less work on my part.
As far as I can determine, the latest time Warhorse could have been fired would be the 1930s. It may have been last fired in WW1, after which it fired my great-uncle home. So the results are not too shabby after all that inactivity, and my results at technology upgrades.
The only problem in firing 50 rounds of GI ball was one stovepipe. I just flicked it away with my finger, the slide closed on a fresh round, and everything went normally. I'll be installing a more modern "aggressive" ejector to prevent a recurrence. This is one reason for test firing your work.
This was also the first, and probably the last, time I fired any weapon using the .357Sig round. It isn't a difficult round to fire, like I found with the .45ACP +P, but it's still a substantial round, as was intended. Being a .357 bullet on a necked-down .40S&W case, it's just about the equivalent of a .357 Magnum. Someone must think it's the cat's meow, but I'll pass. At least I have a barrel, and the remaining 450 rounds to use if I ever need that caliber again.
Other than that, the Sig showed less tendency for me throwing shots to the left, but it wasn't grouping as well as the .45. I'll attribute that to my inexperience with .357Sig round. Still, it was satisfying to see my barrel-fitting efforts work properly.
There must be something about these "semi-oddball" rounds. I came with a box of 50, and went home with 51 pieces of brass. I expect to spend a lot more quality time with the Sig when I put the .40S&W barrel back in. It may be my best compromise for my "hot weapon" for a combination of weapon ergonomics (vey important IMO), magazine capacity, and acceptable ballistic performance.