Hello everyone. I just purchased my first PCP which is the QB Chief 177. Can anyone post how they have their gun adjusted and what pellet they use? I have watch tons of videos' on PCP's but not a whole lot about the QB Chief 177, just mostly unboxing an some features not much else.... Thanks!
You really need a chronograph. The only things to adjust are your hammer spring tension and fill pressure. Fill to max psi (2000psi) then shoot and record velocities down to 1000psi or so. Not a bad idea to record estimated pressures along side of velocity every 250psi or so. I know the gauge isn't great, but get it in the ballpark.
If velocities start low then climb much higher and drop suddenly, you could add striker/hammer tension to help flatten velocities up. Being non regulated, they'll never be flat, but you can get good enough for out to 50 yard target if that's what you're after.
If velocities start high and drop each shot, back off striker tension, until you get a decent velocity curve (low, slightly high, low again).
To adjust striker/hammer tension you'll need an allen wrench, 4mm or so (I've forgotten exactly). In the rear of receiver there's a hole to adjust. If you don't have access to a chrony, set up a target to the furthest distance you plan to shoot regularly (recommend 40 to 60 yards max). If shots land low, then raise beyond expectations as pressure drops then drop again add some striker tension. Post fresh target and repeat until they're grouping good. If you get pellet spiraling (usually 45+ yards), go to a heavier pellet or back off striker tension until it stops.
Also, I don't know if they have changed the valve stem material (poppets) on newer models or not, but probably a good idea to store these guns at low pressure, probably 300psi to 500psi. Otherwise you risk running into valve stem seal issues...
Oh, and keep an eye on your bolt o-rings! If they get chewed up, you'll have to smooth out the lead.