Chaps... I'm not from these parts... Go gentle with me!

I've owned various pistols in the past, from a BSA Scorpion to a CP88...

But, what I'm after is a compact, preferably break barrel or pump (not CO2), with a reasonable amount of power. My reason?

a) To plink whilst out pigeon decoying
b) To apply the "coup de grace", to winged birds, instead of the usual methods.

Any ideas as to what kind of pistol I should be looking at - Probably S/H at that price?

Thanks for any advice.