didn't think to check efficiency, I will next time around. I am used to switching co2 after 2 mags (w/stock bolt), and that's what I was doing yesterday out of habit. being as I had to chrono down, that itself means efficiency is better... but I'll get a better shot count w/ TechT bolt next time.
2k1 Homebuilt Auto-Cocker
TiPX + Zetamags