Troy Hammer machined one for my S510.
It’s a great pellet barrel. It shot everything from 25gr Kings to Barracudas to 34gr heavies very well.
Out of my S510 I settled on shooting FX (or JTS) 34gr at 880. 920 was also a great speed but that dropped the shot count lower than I’d like. That rig made speed finals at RMAC and placed in EFT at EBR this year. It’s performed well for me.
I couldn’t really find a slug that it liked. I didn’t try too hard but I tried over a dozen AVS, H&N, patriot, FX, and Griffin slugs with nothing better than 2.5” at 100 yards. Likely due to the fact that I had Troy cut the chamber for 34gr pellets.