When I had my first multi-choke beretta (silver pigeon III sold on this site) I was given some Carlsen chokes to try in it by a former editor of Target Gun Magazine.
I got a big end reel of paper from a 36 page printing press and went off down the fields on a friends farm. I used every type of cartridge I could beg borrow or steal, with a minimum of five shots of every type of cartridge. Over a measured 40 yards I fired each shot onto a clean piece of paper, then placed a segmented clear acetone 30" circle over the centre of the pattern and counted off the shots in the centre.
There was a clear winner in all of this. My gun and chokes, any of the chokes, preferred Hull Cartridges, with the Sovereign just shading out all the others of the game and clay lead cartridges. But the best performing cartridges of them all were the Lyalvale Hevi-Shot, with all the pellets being within the 30 circle, just, and very evenly spread. This was found to be the case with the 5's and the 3's.
These days I cannot be bothered to do any such testing. But for game shooting I buy Hull fibre wad cartridges in 5 shot, then I use Hevi-shot in 5's for duck and 3's for geese. And after the testing done by BASC I use 3 shot for foxes, although as a young man I preferred 2's for geese and foxes. For clay shooting I use 24gr fibre wad, whatever I can get best for the price.
Simon