Russian Precision Rifle manufacturers, Lobaev Arms, seem to have copied the Sig Bimetal case design and employed it in the creation of .375 CheyTac cartridges. Now while I do not read Russian the only number that I can find that might be representative of the velocity of the projectile is 900 which when converting from meters to feet is 2952, which is standard for the cartridge. So they don't appear to have massively jacked up the pressure, leading me puzzled as to why they made this decision.
The National Institute of Justice (NIJ) have finally after many years (I remember people complaining about them taking forever in 2019) released their new standard for body armor rating, "0101.07".
I have found a thread on a Saiga-12 forum by one Tony Rumore. Who is Tony Rumore? The guy behind Tromix. Who/What is Tromix? Tromix is the company that designed the .458 SOCOM, they've also made a couple other Big bore AR wild cats and some other cool things (you ever see that over under double barrel AR machinegun? Tromix made that)
Anyway back in 2008 Mr. Rumore decided to post all the cool prototypes and one offs his company had made over the last 18 years. There is however a problem, there are too many images for me to post here and they all have photobucket watermarks.
The thread contains everything from Suppressed Thompson Center Break actions, a mosin in .500 S&W, Cut down everything and more.
Link to thread
An unwatermarked duplicate photo of an integrally suppressed Saiga-12.

The thread also brought to my attention the existence of two cartridges I had never heard of before, .338x39 (7.62x39 necked up) and 10mm Magnum (it is what it sounds like)
Mr. Rumore also has a youtube channel that he has started to upload to, which also features some unique guns
Stockless M2 carbine with front grip and elaborate woodworking
Welrod Prototype
A unique SMG held at the British National Firearms Centre, Acquired sometime in 1956. The gun incorporates a Carcano buttstock, SMLE Buttplate, Thompson barrel and magazine and a Martini rear sight
SEAL in Vietnam with a stockless M60 with angled foregrip, Zenitco of Russia would later go on to make such designs prominent in the zeitgeist of the western world
The Innogun Hybrid
The Top barrel acts as a break action and can be had in 12G or a variety of rifle cartridges, the bottom barrel is a magazine fed pump action that can be had in standard rifle cartridges.
Homemade MAC in .38 Super (the cartridges aren't actually huge it's a trick of the camera.
