First are two US military proof rounds, one in 7.62 NATO, the other in 30-06. A standard 7.62mm ball round is shown for comparison.
The cartridge cases are tin-plated for identification. The proof round typically generates 150% of maximum working pressure, and is intended as the critical test of a new weapon. Ammo companies do not like letting these rounds get out of their control. A good rifle might survive several proof firings, but it's flirting with disaster. Once is enough.
Next is an ultra-rare item, an unopened box of .45ACP M12 shotshell rounds. These were developed during WW2 as survival ammunition for .45 users. They are so rare, I couldn't find an image, and I wasn't about to open the sealed box.
The round could not work the action, and was intended to be fed directly into the barrel. It was a last-ditch vey short-range hunting round. Since I couldn't find an example, I included a couple of M9 .45ACP blank rounds. Again, blanks cannot cycle the weapon's action unless various tricks are played. Blanks are also not to be trifled with.
There was enough interest in .45ACP shotshells that some twisted genius invented an improved version about 30 years ago, and convinced RCBS to produce a loading die set, along with a detailed article in the NRA's American Rifleman. The first step involved trimming and forming once-fired .308 rifle brass into the basic cartridge shape. Then came the agonizing steps of making a shot capsule out of a plastic .410 shotshell wad, loading it, and topping it off with a home-made over-shot wad. I say "agonizing" because I made 100 rounds that way (and probably still have 95 in the back of some cabinet somewhere).
The round on the right is the finished hand-loaded product, while the one on the left is a commercial aluminum-cased version, for those people sane enough to buy this rather than spend a small fortune (a complete set of dies today runs almost $200) just for the tooling. I'm not sure if the commercial version is still on the market. The aluminum case usually splits on firing, assuring nobody will try to reload it. Aluminum is also cheaper than brass, and less likely to be declared a "strategic metal".
Surprisingly, these modern shotshells will reliably operate a M1911-type handgun, and can feed properly from the magazine. They still suffer from all the other limitations of the original, though. Nobody was more surprised than me when the things actually worked the first time out.