Awesome little guns. I feel the same way about mine that you do yours. Mine is also a .177.
Shot mine with just boxed Crosman Premiers for a couple years, as it came, no tuning or lube or anything. Finally put in Maccarri's standard HW50s kit (NOT the indoor plinker) with one of his sized Hornet seals and liked it even more after the kit install. Shot cycle is just a quick and solid push, no twisting or torqueing or twangy or any other noise for that matter. I like how it shoots enough that I bought a couple more springs and seals a while back. Should be enough to keep that gun going for the rest of my life.
After installing the ARH kit, I settled on the JSB 7.87 and it puts them out at 710fps when it's warm, and about 720 in colder weather. Consistent as can be. In fact, I bust out the HW50s as a chrono tester when I'm messing with tuning a springer and questioning my fps. I live at 5600feet and have to be happy with 9fpe, which isn't hard when it shoots as accurately as it does.
Only settled on the 7.87s cuz they were the best combination of fpe and trajectory, but the barrel in mine will shoot just about any decent pellet with acceptable accuracy.
Funny thing about the HW50s for me....it was my first quality springer, in fact, it was my first quality airgun and the most I had spent on an airgun at the time. Shoots SOOO good but for some silly reason I had to work through the line up and try some of HW's bigger/heavier/more powerful springers. Sold them all off, but I still have that little HW50s.
Thanks for sharing. You may have just influenced me to spend a little time with my old friend the HW50s tomorrow.