UK Crosman 1377 now restricted to 495 FPS - like Canada

[Zeroexpo1]

Yes, and proved by testing.
2.9 - 3.0mm is the optimum size, going larger will just lose power.

But, you're wasting your time unless you plug the vent hole first

Thanks to all the great info' provided by yourself, Ped, and others, I've ordered the following TP's; 2.5mm, 2.8mm, 3.00mm, and 3.3m.

The 2.8 & 3.00mm should maximise & provide optimum performance.

It'll be interesting to see the results of the 2.5 & 3.3mm, as the 3.3mm variant takes me to nearly 0.132" (3.353mm) as suggested earlier by Ped.

I've recently also purchased several "standard" 1322A026 transfer ports from various sellers, but they're all 3.9mm ID - presumably designed specifically for the 1322, .22 calibre pistol.

I think the 177 pellet will catch & hang on this stock transfer port, so I'll probably use this 1322A026 in my 2240 at a later stage.

I'm just waiting on a Chinese chrony arriving, too.