Before plastic wads, you needed more constriction to get the same tight patterns you can get with less constriction using good, modern loads. The other point, of course, is that many "vintage" doubles were made for all-around hunting purposes--furred game as well as feathers, maybe peppering the fox as he scampered away from the chicken coop. Also, there was a period of time--before the pheasant was well-established across its current range, but after prairie chickens had been greatly reduced--that there simply was not a lot of upland bird hunting available in significant parts of this country. But there were plenty of waterfowl, and with the old lead waterfowl loads, M/F made a lot of sense.
And for upland hunting, I agree with Chuck. A full choke and modern shells give most people a whole lot more range than they can use. And if you hit a bird with full inside 30 yards--and most upland birds are shot inside 30 yards (although not necessarily shot AT!)--the result may not be pretty. I have a pair of Brit guns, one of which was originally choked .040 in the L barrel. I was getting 90%+ patterns at 35 yards from that barrel. Since I had no intention to use it for turkeys, I had that barrel opened a good bit.
Last edited by L. Brown; 12/22/07 02:47 PM.