First off waterfowl hunting and turkey hunting are 2 completely different styles of hunting and shooting. For waterfowl you want to use a choke that gives you a good pattern, for shooting a flying bird, at the distances you shoot. For turkey hunting you want to get a very tight pattern to try to shoot a stationary turkey in the head and neck. Your comparison of steel and tss might make more sense if you looked at just the ballistic properties of the shot type. Or if you were comparing different shot material and chokes for just waterfowl hunting or just turkey hunting.

 

nowell hit the nail on the head. Shooting a turkey is like shooting a rifle. It's that rare instance that a shotgun is actually aimed. Birds and clays the gun is pointed, an even and dense but distributed pattern is the goal. Despite us analyzing our patterns to the nth degree, it's very important to remember that despite the holes in paper the pellets did not arrive at the same time, the pattern is three dimensional, we analyze the result in two dimensions. Esp. if running duplex loads or mixed shot sizes, that will stretch out the pattern.

 

Also, many chokes are now made in full that are steel shot safe. Part of the reason not to use tight chokes was to protect the choke if it was not made strong enough for steel but my understanding is that in the more open chokes, in order to get a similar size pattern between steel and lead at the same distances you needed a more open choke on the steel loads. I don’t know why this would be correct or even if it is correct.

 

First off, thank you for all the responses. But my question is about doing damage to your shotgun. I'll rephrase my question. It is considered unsafe to shoot steel shot through a full choke but it's OK to shoot tungsten through a full choke, even though tungsten is harder than steel. Why is that ? Or am I missing something ?

 

That's up to the individual manufacturers. For example, a popular brand is Browning / Invector Plus chokes. Choke Results

Trulock states for steel, up to Improved Modified is allowed, for TSS------------- Full, Extra-Full, and beyond are all allowed.

 

I think it has something to do with pellet size. With steel you typically increase the pellet size, so for ducks you'd be shooting something on the order of #2, or 3, whereas if you're shooting tungsten you'd likely shoot something much smaller like 7 1/2's

 

But why can he shoot harder TSS through a tight choke but he can't steel? I think that is the basic question he was wanting to know the answer. I am curious myself.

I don't think the size of the shot would matter, hard is hard. Yet I may be wrong.

 

Painter answered the question the OP is asking. The reason full waterfowl chokes are not rated for steel, but extra full Turkey chokes are rated for TSS (even though it’s harder than steel) is due to shot size.

You will read that many aftermarket choke tube manufacturers put shot size and speed restrictions for steel through their long range tubes. Larger steel shot doesn’t constrict as easily as smaller shot. Steel is the least dense of hunting loads, so 7.5 shot steel is essentially useless on waterfowl. Most steel waterfowl loads are #4 or larger and pushed out of a barrel at faster speeds. Usually 1450 to 1550 fps. Greater pressure is needed in the barrel to reach these speeds.

TSS is the most dense of the hunting loads produced. Small shot, such as 7.5, carries much more energy at long range than other loads, even at slower velocities.

As an experiment to help understand the concept, try squeezing a handful of bbs. You will feel them shift to the pressure. Then try squeezing a handful of marbles. The marbles won’t shift as easily.

 

One problem people talk about is "bridging."
Imagine your choke is 1" and your shot size is 0.55". As the shot tries to squeeze through, two pellets end up side-by side and cause a log-jam.
That's a ridiculous exaggeration of the situation (unless one is shooting buckshot)

#9 shot "flows" better because the little balls have many more ways to get out of each-other's way. The group of little balls more "squishy" than a group of big balls.. but at the velocity we are talking about, I wonder if this is really true physics. They hit that choke constriction very fast. However, lore seems clear with steel shot...you can get away with smaller shot size in a tighter choke.

Technically, tungsten is much harder than steel. Both are fully cased in thicker than usual plastic wads. Lots of tungsten recipes even include a little shim of mylar so no little abrasive bits of tungsten can escape the petals slots in the wad.

Comparing lead and steel wads is interesting... it's like comparing deep dish to regular pizza. You could sort them from a pile of regular wads with no effort at all because they are so much thicker.

There is also the matter of the quality of the steel and tempering of cheap chokes vs. top of the line turkey chokes.

 

Steel shot = large size shot. TSS = small size shot. Small shot flows through a choke easier. An easy illustration of how large and small shot flow differently can be seen in reloading. You never hear of shot bridging in a drop tube with #9 skeet loads, but it happens fairly often with #4 or #2 field loads.

 

That makes sense to me, thanks for the extra color.

 

Thank you for all your great answers. Really appreciated. The difference in shot size was my initial thought and makes perfect sense.

 

Other than Turkey hunters I have never heard of TSS shooters shooting tight chokes. Both TSS and Steel shot shoot tighter patterns than lead shot dose.

TSS shot is perfectly round and very hard so it doesn't spread out like lead shot dose.

With the much higher pellet counts of the smaller TSS shot you really don't need a tight pattern to have a dense enough pattern to make clean kills. Steel shot also patterns tighter than lead shot so most hunters don't use chokes tighter than a Modified choke for shooting steel shot, especially with steel BB shot and bigger.

1-1/4 oz of steel #1 shot has about 127 pellets, at 1500 fps it gets 2.50" of gel penetration at 25.7 yards.
1-1/4 oz of steel BB shot has about 90 pellets, at 1500 fps it gets 2.50" of gel penetration at 39.4 yards.
1-1/4 oz of TSS #7 shot has about 229 pellets, at 1300 fps it gets 2.50" of gel penetration at 67.6 yards.

1-1/2 oz of TSS #9 shot has about 536 pellets, at 1300 fps it gets 1.50" of gel penetration at 68.5 yards.
1-7/8 oz of Lead #5 shot has about 325 pellets, at 1300 fps it gets 1.50" of gel penetration at 55.6 yards.

With the much higher pellet counts of smaller TSS shot you don't need a real tight pattern to get a dense enough pattern to make clean kills. You also don't need to shoot heavy loads with TSS shot.

1-1/2 oz of TSS #9 shot has right at 65% more pellets than 1-7/8 oz of lead #5 shot.
1 oz of TSS #7 shot has right at 104% more pellets than 1-1/4 oz of steel BB shot.

 

A thousand tests is worth a million guesses. Scott Trulock has shot TSS #7 - TSS #9 through every conceivable 17-4 SS choke he makes and has yet to damage a choke.

 

With Bob being so entoned to TSS shot let's not forget a shotgun was designed for
targets inside of one's ability ? Those shots after 55 to 60 yds are still Hail marys
and going to the plug to do them , are costly ! I enjoy pass-shooting as much as the
next guy but I feel confident knowing the ballistic of my loads , along with the time
I've spent on the patterning board (at those distances) to reaffirm I have a 65% chance
of success !

 

Those shots after 55 to 60 yds are still Hail marys
and going to the plug to do them , are costly ! I enjoy pass-shooting as much as the
next guy but I feel confident knowing the ballistic of my loads , along with the time
I've spent on the patterning board (at those distances) to reaffirm I have a 65% chance
of success !

All you have to do is pull the trigger twice, and by your estimation your success rate is 130%.