I wonder if the 4.50 or 4.52 ftts will group better at 40 yds.Thanks for the info you've shared on this gun with a .177 barrel.
An Occam’s Razor approach 👍
Time for accuracy tests.I'll keep this short and sweet.The stock barrel has the typical Crosman loose bore....The loose 3622 barrel didn't shoot less than 1.25" CTC on either gun with 5 shots.
Always follow the manufacturers safety guidelines.A stock 3622 can be safely pumped to 2K psi. My 3622 valve is pinned with 3 Prod screws and it (Prod) can take 3K psi.The Prod has a 3/4" ID tube so a 3X pinned 5/8" ID tube will easily handle that.https://www.gatewaytoairguns.org/GTA/index.php?topic=213423.msg156522876#msg1565228763.14 x R2 x fill pressure=force pushing on the valve3/4" ID tube @ 3.0K psi=1325 psi5/8" ID tube @ 3.0K psi=0929 psi5/8" ID tube @ 4.5K psi=1380 psi