Crosman R1 Full auto 4,5 mm CO2 GBB & chrono. 

Measured with Umarex 0,35 g steel BB + ASG Blaster 0,13 g plastic BB & fresh 2 x CO2 cartridges.Thread is 14 mm CCW (as in airsoft).NO 430 FPS,NO 1400 RPM ( FPS and RPM are different from the manufacturer's data when using standard ammunition 0.35g steel BB ! ).Approx 100 shots with two co2 cartridges.Weight : 2750 g.Distance 6 m.👎
After lubrication, the FPS increased to +- 400 (122 m/s).