-13f, pcps and chrono

[Blutroop]

So now that I am back to a regular 40 hr work week job I am down to weekends to shoot over a chrono. Since I am in Alaska I am further limited to close to 12 noon on sunny days. Even still I have to set the chrono on its side and shoot besides it to have enough light. So when the sun piped out this Saturday I went a mile away to my sunny spot even though it was -13 degrees.  I have my .172 barrel on my prod now as my prod/disco double is a pita to pump by hand from 0 often. My strings had been peaking around 2000-2200 so I only pumped to about 2800 ish. I only have the prod stock gauge and hill pump gauge to go off and there’s only 300 difference between the two. Prod matches my other gauges though.
1st shot actually read and was 902! 47fpe! Then the next was 823, then 736 so I could tell already I missed my peak #. I stopped there. I was at 2600 ish
1st. should I expect numbers close to these when it’s above freezing? I’d like to use this for calling coyotes in winter and grouse in summer.
2nd. I’ve found a .45 wire dia. Spring (the heaviest I’ve been able to locate so far) and  shortened the lightweight valve spring as much as I can. I opened a valve up as much as I think I can. Bore size barrel and tp. Turned a bolt down probably to far. Am I about maxed out with this platform?

[rsterne]

Is that with a PRod air tube, which is only 65 cc (4 CI)?….

Bob

[Blutroop]

Yes, I have a disco length double tube but got tired of pumping it up every time I tweaked another valve.