Dont know what kind of shotgun your shooting but in my doubles I load # 7 shot right barrel backed up with # 4 shot left barrel. ic and mod choke. If hunting stocked birds load up on 7 in both. If hunting wild birds late season carry some # 2 shot also, all depends what the birds are doing. If your using pushers and blockers ( usually used in S.D. on game preserves with stocked birds go strait # 4 shot. You also dont need 3" mag shells 2 3/4 work just fine, I shoot 2 1/2 shells kills them real dead. But in all honesty I've killed more birds with 7 shot than any thing else, inside 20 yds you have alot more pellets from 7 than 4 hitting the bird pretty much smokes them, but you have got to be prepared for any thing, carry #7 +#4 and I would have a box of #2 just in case. If your using a 28 ga go strait #6 dont shoot past 20 yards
How much are we talking?Temperatures at zero, drops velocity a lot on shotgun loads...more than you would ever imagine.
Man, for some reason I have always wanted a 16ga. I have been eyeballing the browning Citori's...My favorite load is this or as close as I can get to it. 1 oz to 1-1/8 ox of #5 at a high speed works great. I have loaded my own. Fox 16ga AE Krupp 30" 0.012" right choke and 0.024" left.
Man, for some reason I have always wanted a 16ga. I have been eyeballing the browning Citori's...