I've shot up a lot of butcher paper on barb wire over the years with many different shotguns and faster ain't better. I look for 1200 FPS and pattern quality. I'm convinced good uniform patterns kill a lot more birds than fast. We patterned some of the screaming fast waterfowl loads a couple of years ago.......ugly. With some of the 1400 FPS stuff you can fly a small plane thru the holes and ragged dispersion of shot. Slow it down, try lighter loads of 7 1/2 and go back to the pattern board, try different chokes. Find some combination the gun likes before going back to the field.

After reading through four pages on this subject I have some random thoughts.

The OP didn't mention if the ammo being used was factory or reloads. In either case the problem could be the type of wads used. Cheap factory stuff can have terrible wadding & I've found some of this bottom shelf stuff to have awful patterns.

The 28ga in general is famous for having great patterning due to it being a square load in 3/4oz loadings. I've tried heavier shot loads only to revert back to the basics of what the gauge is known for. 3/4oz of 71/2 or 6's will get the job done as long as you keep things in perspective for the type of game you're shooting.

I'm thinking that Dylan simply was shooting some ammo that his gun just didn't pattern well & he might simply need to take several different loadings to the pattern board and see what works best through his gun.

I've shot a bunch of early season wild pheasants over the years with a 28ga and loved every minute of it, but I also changed over to a 20 or 16 later in the season when I felt the need to use larger shot sizes when the birds had their full winter plumage & potentially needing to shoot at longer ranges.

Bottom line is to find out what works best in your gun and keep things between the guard rails for the gauge of the gun and the game you're hunting.

Parker repro 28ga guns are light in weight and delightful to carry in the field, but they can also be as tough on the shooter as they are on what you're shooting at because of this. Between being under 6lb's in weight and having a skeleton butt plate, they can have some uncomfortable recoil when shooting heavy fast loads through them. Keep things in perspective & enjoy the gun & gauge for what it is.

I admit to buying some cheap shells for my repro 28ga.
1oz 6 shot 1220 fps for under $7 a box.
Would these be just too heavy for the repro? They do kick.
I thought being a modern gun, the repro should handle them.
Thoughts??

If I wanted to shoot 1 oz loads I’d use a 12 or 20. Save your 1 oz 28 loads for the Jamomatic Bennelli or Beretta. Slow your load down and use 3/4 oz.

Have you perhaps considered gun fit?

Clark, what Ed said. This is not rocket science. Less is actually more when it comes to shotguns. Save the 1oz stuff for your 12ga.

My standard 12 ga. load is 1 oz. lead or bismuth, 7/8 in the 16 and 20. On the rare occasion I hunt geese anymore....rhino roller 3 1/2" BBB for the Super X 12 ga. (not my Parkers) and 6K PSI 2 7/8" BB bismuth in my 10s (Parkers).

I certainly see why they were on sale :)
No more of those 1 oz!
But back to pattern, I’ve been intrigued by the vintage British guns
With 2” chambers - those shells must be really light.
Also I’m curious about “shot string” and how flat the shot hits a target.
How is the barrel or choke altered to affect the flatness of the shot.
Is it more important to have a flat strike or a teardrop shaped impact of the
Shot hitting a target?

I'm not sure what you mean by flat strike/teardrop impact.

The birds don't care as long as it hits'em!

Not sure if I’m using the correct term to describe
The idea that not all of the shot coming out of the barrel travels at the same velocity.
Some is a little slower and follows the lead shot to the target.
Somewhere I saw a picture of shot a teardrop effect (or sideways raindrop) to explain
This phenomena.
I’m probably overthinking it all, but still the question,
Is a flat impact more or less desirable than a bludgeon of shot hitting the target.