Okay, so the Kent Bismuth #4 shot was the heaviest at 30 grams.
Winchester Dry Lok #3 shot was the second heaviest at 27 grams.
Hevi shot hevi metal #4 shot was the lightest at 22 grams.

But interesting thing, the hevi metal was about 50/50 different size shot, being #4 and #6 shot. Whats up with that?

And then, what in the world is the seed looking stuff that was in the hevi-shot shell. It was at the end of the shell where the casing opens up.

I know pics are in ounces, i changed the scale afterwards, just didn't take pics of that.

Heavy metal uses biodegradable flax seed as a filler instead of plastic. Heavy metal uses a mix of ‘heavy alloy shot’ (which is smaller, denser and lighter nr 6 shot in your case, sometimes nr 5) and a layer of nr 4 steel shot in your case.

So a heavy metal nr 3 load (my favorite all around load) will have a mix of steel nr 3 and alloy nr 4 or 5

Your next test should be to open a nr 4 heavyshot and a nr 4 heavy X tungsten

Top of the line in order:

Heavy shot
Tungsten
Bismuth
Heavy metal
Steel

What is the difference between hevi-shot heavy metal and heavy steel?

Hevi steel is just 100% steel
Hevi metal is a mix of hevi shot (alloy) and steel

Yea, Hevi Metal is a duplex load. I can't help but think no matter how it looks on a pattern board, it still has to play hell on the shot string.

Shells with Hevi Shot can vary in actual density between different trade name loads or when the load was made. Goose vs duck loads and 12ga vs 20ga may or may not have different density shot between them. And between brands also using tungsten/nickel/iron. The earlier offerings for the most part usually had a much higher density than the current ones. IMO, the best duck load Environ ever offered was the original Heavy Metal branded load that used all hevi shot with a density just a little less than lead and sold it for a very affordable price compared to the more dense loads. It became to costly to make and changed to a duplex load but they did not change the name. It was a big controversy at the time, because the company used the same "Hevi Metal" product name for the duplex load when they discontinued the all hevi shot "Hevi Metal" load. To this day I think a lot of people think their Hevi Metal shells only contain heavier than steel tungsten/nickel/iron hevi shot.

I remembered a "don't see that every day" kinda post about the Hevi Metal load. Trout-killer cut one open and it had live bugs in it.

https://texashuntingforum.com/forum/ubbthreads.php/ubb/showflat/Number/4653281/

I was thinking the same thing on shot string.
I think a way to test that is to shoot at something in the water at 40 yards. Put a camera on the side and check the difference.

I'll have to find a regular #4 shot shell and check it out. See what the weight difference is.
That Kent bismuth is obviously heavy, but is it worth it?

I got lucky and found the heavy metal at bps on sale for ~$13 for a box, so I picked up a couple.

The new Kent Bismuth waterfowl loads are outstanding. I’d take them over hevi-x or hevi-metal in any configuration.

Sorting through the HEVI products can be confusing. Heck their catalog isn't much help either, but the previous posts are accurate. Hevi-Steel (and Hevi-Teal for that matter) are 100% steel loads. They don't contain any form of tungsten alloy. Hevi-X contains 100% tungsten alloy BUT the % of tungsten contained within the alloy is not the same as the more expensive Hevi-Shot.

Personally, I'm going to try several variations of the new Bismuth loads from Kent to see how they pattern before next season after all the positive feedback I've heard.

I havent done much duck hunting this season, but I did buy a few boxes of Kent Bismuth in 12 and 20 to use in older guns on other game and just to try it out. I patterned a couple shells at the lease and they patterned the same as comparable lead. Game and birds I shot with it fell dead. I am putting it ahead over the Hevi stuff as well. IMO, the best non tox shell out there is Kent Tungsten Matrix, but it is so expensive.