No 335 action Tony as I've been doing a bit with three previous projects; two hw35's and a Beeman R1. The Beeman is short stroked and has had a slimtech style moderator added, but with a twist as at about 3/4 along it's length it splits to reveal a 1/2" unf thread. The hw35's have both gone for new piston and custom guides and Ive fitted a sleeve on one and a moderator on the other. I've been shooting these side by side; all shooting nicely at 11.5 ft/lb ish but the two 35's edge it on recoil just, mainly due to the piston weight I guess.