Oh well.... That was many years ago. Water under the bridge. I think I saw a listing of chokes by gauge and the .020 was listed as I mod for the 28. Likely mis read by me.....

I will just relate my experience with a 30" barrel RBL custom I had built. I had it choked Q1 and Q2, which equated to maybe .001 and about .004. I bought it for preserve hunting and it served well, although I finally settled on spreader loads for the first barrel and a normal load for the second (both Polywad) because it was hitting the first bird too hard. Both number 8 shot. I ordered the long barrels to control the swing. It worked perfectly for several years. My grown daughter decided to give it a try and it became "her" gun. She did well on the first covie shot but was slow on the second. I switched her to a spreader load on the first and one of the old "Gram Krack'r" loads on the second. This was a 5/8oz load of nickel plated 5's loaded with a full dose of filler. She killed the long shots dead as a hammer.

I later used it on doves in the fields shooting 1 oz of number 8 in the first barrel and the GramK'r load in the second. Their seemed to be no end to the killing range of the second barrel. It killed pheasants just as easily at 40-45 yds. I nevered patterend it but it seemed like those loads had about the same distance at whatever distance I shot.

I have noticed with hunting guns, if the gun will pattern properly I really like shooting 5 or 6 shot because they kill with less hits and are much easier to deal with for the table.

What is the Pattern location
 

You will have to answer your own question on your ability to put the shot pattern where the target is going. I doubt many adult men would notice the difference between a 26" and a 28" barrel length on a 28 gauge side x side. So, what you're talking about is pattern density and how you place it while intercepting the target. So on the skeet field or 5-stand or sporting range, do you break targets into big pieces or do you center the pattern on the target and smoke them? If you're a poor or sloppy shooter, you'll probably need a more open choke to catch the edges of the bigger pattern, which will probably result in wounded birds and cripples. Better shooting solves those issues. It's all about focus.
But, you could buy these new shells, at $10 a piece, and kill whatever's out there. And these are all about affordability.

Wow. 1 1/2 ounces in a 28 gauge. I would like to have one of those shells to take apart.

Whatever 28ga you get take it out and shoot the snot out of it. I've hunted with a 30" 28, both SxS and O/U for years and truly believe that the longer barrels are a huge benefit to me and I use them on just about any upland bird and waterfowl. I have found that the smallbores and light shot charges perform much better with tighter chokes. It took me many years to realize that choke is your friend.

Always remember that all of these older guns were designed to shoot paper shells with fiber wads. They needed more choke to hold patterns at longer ranges. That is why there are more tight choked guns of all gauges out there. Modern ammo will usually give you one step in choke compared to the older paper ammo.

Tom
For hunting in close cover like most of New England I have always felt the 26” barrels are far superior to longer barrel shotguns. I have used 26, 28 and 30. If the cover is open like on the cape the 28” or 30” may be better. In maine and New Hampshire and north and western mass the 26 is the best.
As far as choke goes I suggest you take the guns and do some patterning with the different chokes at 20, 30 and 40 yards. Then try 9, 8, 7-1/2 and 6s. I think you will be surprised with the outcome. I did this and the difference is minor, except for a cyl compared to full at 30 or 40 yards.
I generally feel that when birds are close almost any choke will work. For that second shot the mod and full are much better.
I also had ordered a 28 gauge gun and had it made with tighter chokes ic and full. The reason was if I was fortunate enough to hit the bird I wanted dead not having to chase it around and maybe losing it.
The gun fit on upland shotguns is paramount.
Bob

Choke is irrelevant. Don’t worry about it. Put the muzzles at the right place and any choke will kill a bird or turn a clay into diesel smoke. Gun fit is more important than barrel length too. If the gun doesn’t fit, it won’t hit! Then again, even a blind nut finds a squirrel.

No gun or choke are really the same. You have to pattern the gun to see which loads and shot work best with each choke.

I really don't think 26 or 28" barrels make much of a difference when you are navigating through Woodcock cover.

For the most part, my 28 gauge is choked Skeet/IC from beginning to end of Grouse/Woodcock seasons.

If your plan is to take game or break targets, then gun fit is the only thing that matters. Everything else is between the ears.