I have an Air Arms S400F Classic in .177 which I use for target shooting, very accurate and reliable gun. Made in England as well, no less (aside from the stock I think). For knocking down pigeons you probably want a multishot variety, so the S410 or S510 even, depends on your budget. If you want to know more about that, watch huntersvermin on YouTube... loads of vermin shooting with various air rifles.
The PCP reservoir in the S400F has enough for about 70-80 shots on a single fill (180 bar-ish).
Daystates are creme-de-la-creme, but with a price tag to match.