So it’s steel 2’s for pheasants.

[Dunwaters]

However even for a 1 1/8 oz cartridge you will not get 1400FPS from a standard steel shot cartridge as it exceeds the CIP momentum limit of 12Ns.

((1.125 x 28.3495)/1000)x 426.72 = 13.6 Ns

CIP limits the performance of standard steel shot, to go past that you need HP steel.

So your 1 1/8 and 1 1/4 oz in standard steel will be much slower, e.g. 376ms or 1234fps for the 1 1/8 oz cartridges (less again for the 1 1/4 oz) with a maximum shot size of 3.25mm all of which will limit the scope of use for them compared to HP steel.

We are just not used to selecting a cartridge by the distance we intend to shoot at, rather we currently select a lead shot cartridge by quarry.

So just get a gun that can handle HP steel?
It seems to solve a lot of problems.
Did you notice the comments on chokes?
I think your maximum shot size of 3.25mm is linked to a recommendation of not more than “modified”restriction in chokes not specifically designed for steel, with steel compatible chokes it seems that you can exceed that recommendation even in non steel barrels provided you have at least 2 3/4” proofed chambers.
I’ll be checking into that in the new year.
You may select your cartridge based solely on quarry, personally I select mine based on both the target species and how I expect to shoot them.
I select different guns and chokes too.
For birds over pointers and general rough shooting I use a maximum of 30Gm lead 6’s, ( I couldn’t source non lead ) in a SBS.
On a pure snipe and woodcock day I shoot 28Gm 7.5’s with a couple of 6’s in my pocket just in case a duck or a pheasant gets unlucky.
On my rare forays into the world of driven game, I use from 32 to 36Gm of 6‘s to 4’s depending on the game and the drive, with heavy 4’s used predominantly for high duck, fired through a full choke and from a heavier sporting gun.
Given the wide variety of shotgun loads available, I don’t think I’m the only one doing it this way either.