I own a .44spl that I love. I bought, put 50 rounds thru, and sold the .357 model hammerless.
I don't know what it was. The .44 has a nice trigger, has gone over 400 rounds without a hitch, it's a keeper.
The .357 hammerless started to bind (cylinder) within the first 6 shots. It didn't get better, it got worse. The trigger sucked. It had a hard pull and then it "paused" and then it would fire. The pause was just long enough to throw off aim.
I didn't want to mess with it so I just sold it. I don't know (it may be just me, I don't like that internal lock thing) but the .44spl without it, no problems, the .357 with it, many problems.
Wayne