Can't prove it but I believe that my 20 Big XL loads have more punch than my old 3" 12 gauge mag blends used to have. And it ain't nearly as unpleasant to shoot the 20 as it was the 12.
That said, I hunted this year with home rolled TSS in a pop gun (410 Mossberg pump with a fixed choke). Kilt one at 24 yards.
Had neck surgery at Thanksgiving and was just thankful to be able to get out in the turkey woods. Doc originally told me wouldn't be able to hunt this year (or fish from a boat). I figured out how to strap the 410 to a bog pod so I could shoot it without stripping the screws and plates they put in my neck at the end of November. I spent 3 hours before the bird finally got so cranked up he flew over a creek to die. First gobble at 6:40 am. Last breath at 9:43 am.
Might just use the 410 next year (226 pellets in 10" circle from 30 yards when sighted in pre-season). That thing's light and mighty easy to tote around.
BTW, I still believe that more birds are kilt with patience than good calling.
You can get away with some of the recoil by going to a 20 and typically you will be carrying a lighter gun. The 20 will throw a better pattern than any 12 ga set up out there, unless it's a 12 ga shooting tss, and I havent gotten that much better patterns out of my 12s with tss
On the recoil, the 30s with a 1 5/8 load will still pack a punch, but nothing like a 3.5 load
I got 445 pellets in the 10” with my last 12ga load and decided I really didn’t need them to be that dead. Got a 20ga Benelli M2 and never looked back. That thing is a stone cold turkey killer and still puts 300+ on the money.