TargetTalk

My older Tau-7 doesn't quite manage to complete a 60 shot session before running low on co2, I have backed out screw #20 but didn't see any change, I'm using quite old crosman powerlets that seem to vary some in weight, but that shouldn't affect adjusting the vel.
I wonder if ISSF rules allow for changing co2 after 30 or so shots? Don't have a chrono.

You can fill up your gun at any time, but you must leave the line.

A typical Tau-7 should get about 7 shots per gram of CO2, so a 12 gram cartridge should just get you through a match unless the velocity is cranked up, there is a leak, or your cartridges are a bit short on CO2.

if you change cartridges mid-match, make sure you swap the piercing caps so the O-ring on the first one has time to recover.