Seems most everything needing pondering has been pondered!
My thought here is more about Setterman than TSS or a 20 ga vs. a 12 ga.
But before going forward and to provide full disclosure,
I, myself, do in fact do most of my turkey hunting now with a 20 ga.
THAT, my friend, is
one of the most powerful, arse-kicking LONG RANGE turkey loads ever formulated!
Believing I have some idea as to how you typically turkey hunt, and your thoughts on turkey hunting period,
I am just truly baffled as to why YOU would choose to load your gun with such a shell?!?!?
I suspect, 90% of the birds you have killed the last many years would been 1-shot dead had you been using that same 12ga gun with a once common 1 1/4 oz lead #6 "squirrel" shell?
YOUR average shot, what, 27 yards?
That said, I think it is and you are "smart" to have jumped on the TSS bandwagon, simply for the fact you can achieve more reliable, consistently dense (without "hole" & "flyers") like we experience with lead pellets. But, a 1 1/2 oz 12 ga load of TSS #9 may have better patterns
AND exceed the high-probability lethal range of a 2 oz load of lead #5s.
Why go up to 2 1/2 oz of TSS when you were shooting 2 oz lead loads?
I do agree that we normally don't notice recoil when shooting a turkey, no matter what shell is in the chamber. But at the range, I'm much happier with my lighter loaded 20 ga.
If both guns are loaded with TSS, a 20 cannot outperform a 12.
But a 20
with TSS can roughly equal or exceed the high-probability killing range of a 12
loaded with lead.