I just got back from the second range trip with my new to me BA50. The first time the trigger felt gritty and had a lot of take up before release. I stoned the sear and trigger and now it is smooth and breaks crisp, but still extremely heavy.
I cannot get consistent groups because of the heavy trigger pull. Try as I might, I wind up torqueing the gun from pulling so hard and shooting more of a pattern than group.
When I got home, I swapped the hammer spring for a standard AR15 hammer spring. OMG what an improvement. I will try it tomorrow afternoon if I have time. I'm just worried it may not set off primers reliably. I needed to order some higher rings to mount an Athlon BTR gen II 6-25x50, so I added a Wolf extra power spring to the order to see how it works.