"The AK12 would work fine. A Russian AK wouldn't fail like this! But the AR15 got guys killed in Vietnam! etc, etc, etc..."
Hand wringing, consternation and ridiculous comments like these have been streaming in non stop since our AR15 and AKM mud test videos were released a 1 year ago. The AK and Vz58 videos have even been used in Russian and Ukrainian media propaganda.
There seems to be a very significant gulf of misunderstanding in that these tests test the mechanical design of the weapon in a specific event; they're not indicative of any of the other benefits or detriments of that particular weapon platform.
We got our hands on two Vietnam era AR15s: The first and primary is a Colt SP1 - The real deal with original metal follower 20 round surplus magazines. Triangular handguards, no forward assist, no brass deflector, no protective gate around the mag release. It's functionally identical in every way to the rifle in the photo used for the thumbnail of this video besides not being select fire.
The other is a Troy GAU-5/A/A commemorative replica as used in the famous Son Tay raid in 1970.
What's the truth about Vietnam era AR15s? Did they get men killed? Maybe, but maybe not for the reasons understood in the frequently wrong but oh-so-sure-of-itself "common knowledge" base.
So what to do? InRange mud tests them both, of course!
Original AR15 mud test: https://www.full30.com/video/30a1f036a5143172f5da39cf50f46360
Original AKM mud test: https://www.full30.com/video/753d617d16a9cb6c09526519a0740313