Tim,
TSS stands for Tungsten Super Shot.
It's a very dense alloy that is approx 18.1gm/cc
For comparison lead is a touch over 11gm/cc.
TSS shot will have the same penetration energy as a lead pellet 5 sizes larger!
A TSS #9 will penetrate about the same as a lead #4 at the same velocity.
The advantage is obvious.....for the same weight load you can squeeze a whole bunch more of them into the gun!
A 1 5/8oz load of TSS #9 is about 582 pellets. Compare that to lead #5 shot which would have 283 pellets in the same weight load!
It's all about pattern density.
TSS is very heavy, very round,very hard, and very polished. It by nature wants to stay flying straight.
I don't have to worry about gaps in the pattern or only clipping a bird with a couple pellets if I keep the gun pointed straight.
If I do my part, the gun will drop a bird everytime at any range I am comfortable shooting. Which is out to about 45yds.(even though the pattern integrity makes it lethal even further)
No guess work or wondering if it MIGHT kill a gobbler at that range?
I know from many hours of testing that it will do it every time.
And it's just an absolute hammer.
Also remember I am shooting a Colerain choked barrel which helps a lot. Combined with the TSS I'm not giving up much of anything vs even modern shotguns shooting shotshells loaded with the same stuff.
The trade off? I can't use any sort of protective shot cup in the bore because of the choke. Is it scratching the barrel? A little, there's no denying that, but it's also very fine because of the size of the shot and how polished it is.
Larger Hevi shot or Heavyweight pellets would score these soft barrels terribly but the tiny TSS is very minimal.
And honestly I don't care one bit.
The gun is for bopping turkeys every year and now that it's filed and dialed and the load established......I won't shoot that barrel out in my lifetime taking 1-4 shots per year.
It's not a "safe queen" that's for sure. It gets drug up and down and all over each season and it's got it's share of love marks on it.
Wouldn't have it any other way!
The load is super simple.
105grs of Swiss 2F
(1) thin overshot card over the powder
(2) 20ga 1/8" dry wool wads stacked.
1 5/8oz (711 gr) of TSS #9 (or #8 in NY)
topped with (2) thin overshot cards.
Remember you have to weigh these shot loads. The difference in density vs lead means you can't use a shot dipper.
All the components in front of and behind the shot column are very light which will keep anything from blowing up through the pattern.
They just create a nice gas seal and then spin off the back.
That's it.
Keep the bore sparkly clean and dry between shots.
Fouling makes a big difference in pattern density and integrity.
Always test on a clean bore each shot.