I've shot woodies both decoyed and going to roost for 20 years or so. Goodness only knows how many thousand woodies I've accounted for, I certainly don't.
Time was that I would be out most weekends with a friend on the woodies, we became semi pros, we got our cartridge to kill ratio down to 1.4 to 1 on decoyed woodies. Sadly I now don't get out as much nowadays due to loss of permissions.
Some years ago McF and I experimented with 7.5s on woodies, and gave them up as a bad job. Our lust for a cheaper cartridge was the driving force, and this was in the days when a cartridge cost around 8 pence, and the game dealers paid 10 pence for a fresh woodie.
Killing live quarry is vastly different to breaking a clay. Killing requires penetration, this requires force, force = mass x acceleration. Therefore the larger the pellet the deeper the penetration will be. There are no degrees of dead; but we found that utilising clay cartridges for woodies limited our range to some degree, and the number of follow up shots required to kill injured birds rather than leave the hide and disturb the set up more than absorbed any savings that we made, so they actually cost us more money not less.
For many years I shot Eley HB Pigeon 32gms 6.5s fibre wads. They are a fine cartridge for woodies. For obvious reasons I'm now shooting Fiocchi Pigeon Load; they do what they say on the tin. I can't claim that they are better, they certainly arn't worse. They kill pigeons dead.
When you kill live quarry you have a responsibility to do so humanely. Part of that responsibility lies in the selection of appropriate ammunition, cost should not enter into this equation, remember you are killing, not simply breaking. If you want to leave pigeon untill they have almost landed in a pattern set out so close to the hide that you can almost spit into its centre you will kill pigeon with 7.5; but on days when pigeon don't decoy well, or at all, and you sucumb to the temptation to take a shot at a slightly longer distance don't be surprised when you see clouds of feathers but birds flying on, or birds flapping about on the ground requiring either despatch by a second shot or other means.
I served a proper apprenticeship, I was taught by real craftsmen, they taught me to always use the proper tool for the job; if you don't have one make one! They were wise words. On the odd occasion when I have been tempted to utilise cheap tools or substitute a fit all, there has always been a price to pay, usually requiring a plaster or stitches.
We all like to think that we shoot responsibly, lets make sure that we actually do.
webber