Did what I needed it to.
I bought this to restore a Sentinel that had been abused by the previous owner. When I put the spring in at first, it made the prime considerably harder, but nothing an adult couldn't do. However, it also made the trigger pull very hard, to the point I had some serious issues pulling it. I ended up cutting half a coil off, and that made so much of difference. Trigger pull was very comfortable, the prime was a bit more comfortable, and I think there was insignificant (if any) drop in FPS (don't have a chrony, so I can't be sure, just based on range and impact force at point blank range). All in all, a great spring, but I think cutting half a coil off makes it even better.