Is it right to assume that if a 20 gauge can can bring down pheasant with a 1oz load, a 28 can also? Or are there other factors involved?
There are pheasant, and then there are pheasant. Game farm pheasant are sometimes hunted with #8 shot due to nearby residences, etc. However, wild pheasant are tougher, and #4,5 and 6 are common shot.
As the bore gets smaller, patterns with big shot degrade, and shot strings lengthen. 1 oz. of #4 through a 28 probably won't work quite the same as 1 oz. of #4 through a 20.
20 Gauge is a much better all-around choice IMHO. Most 28 Gauge guns are about the same weight as 20s. Brownings are actually
heavier; Berettas weigh an ounce or two less.
With 28 Gauge, you'll pretty much have to reload if you shoot targets (or, if you have enough money to shoot factory 28s all the time, you have enough money to buy several guns anyway). Factory 28, even in the
best of times for lead prices, is more than twice the cost of 20.
The smaller the hull, the harder it is to reload, and the shorter its reloading life. You won't find many 28 Gauge hulls lying around at the range, either. 28 shooters almost all reload, and they eagerly take empty hulls from the few who don't. 12 and 20 Gauge reload easily, but it's cheap enough that you really don't need to care.
With shotguns, it's really the gun that matters, more than the shell in it. A few 28s really offer something special (the Ruger Red Label and Remington Wingmaster 28 Gauge guns are a lot lighter and quicker than the 20 Gauge versions). Most don't, until you get into the really high-end stuff.
A shotguns is like a golf club. It's the way it handles that matters, more than anything.
I think that 12 Gauge is downright
philistine for some applications
. For Trap, and to start out shooting Skeet, though, I wouldn't shoot anything else. (Okay, I sometimes have shot Trap with my 16 Gauge double, but only for testing and practice.)
Trap moves slow and smooth; Skeet moves fast and smooth. A small, light gun is snappy, which is great for quail, but a serious handicap when learning to swing through the target well. It's not the
payload that's the handicap; it's the gun.
And no matter what you think now, if you're missing half your Trap targets, it won't be fun for long.
I've seen 28s and even .410s at the Trap range. Generally, they were in the hands of a couple of VERY skilled shooters with 30+ years of experience, challenging each other to a contest. Guys who score more 25s in a day than most people ever shoot
still had a hard time shooting American Trap with little guns.
If you don't want a 12, the 20 really offers the most: a light gun, 3" chambers for steel shot when needed, and wide and cheap ammo availability for targets and birds.
28 only offers a light gun, and that's not a plus for most of your purposes.
That's my take. It's worth every penny you paid for it.