1) Having the appropriate size barrel matters- I brought two guns with me, my 3-gun competition Benelli M2 with a 24" barrel, and my Benelli Vinci with a 28" barrel. I was excited to shoot my M2 because of the mag tube extension that brings my capacity up to 13 shells, but I simply cannot reach out as far as my Vinci with the 28" barrel. I had to be much more patient letting the doves get closer to me, or I missed many shots since they were simply out of range. Today I shot my 28" Vinci and I'm hitting many more targets.
2) Having more is not necessarily a good thing- With 13 rounds in my M2, I think it encouraged me to shoot more and therefore waste ammo since I was also missing more. The gun is heavier which can get tiring after a few hours out in the field. The upside of having 13 rounds in the gun is that I can spend more time eyeing the skies, but honestly I've been hitting more birds with my 4 round Vinci.
Now, the M2's shorter barrel greatly contributed to my increase in missed shots, so it's not a totally fair comparison. I'd want to put a 28" barrel on my M2 to be fair to the Vinci. I'll do that one of these days.
4) Lastly, speed loaders have been super useful. Here I've got three different types: TacCom, andAP Custom. When my hand tires of one technique I can switch to the next. Having the ability to load quickly enables me to turn my attention back to the sky.
A video of the hunt is forthcoming, and I'll post it when live!