There's not a ton written about this that I can find, but cracks are appearing in the US military's plan to replace the M4 with a heavier battle rifle designed to defeat body armor. Sig Sauer, which also holds contracts for the current generation pistol and LMG, won a contract last year to also provide the US military with a new rifle. This rifle is to be called the XM7. The civilian equivalent is the Sig Spear. Calling this thing an assault rifle is a bit of a stretch, as it is very heavy and uses heavy ammunition. It turns out that the rifle is failing to penetrate modern body armor without the use of tungsten bullets. Also its reliability is questionable.
I think InRangeTV has always been pretty insistent on not taking mud tests too seriously. It's not a scientific test or anything.
Yeah, its pretty much the worst case scenario imaginable as far as mud goes, and also usually just done once.
It is funny they keep being referenced by random media outlets trying to make a point about guns, I think a clip of an AK variant got featured on RT(or another East European media org) once? Which is particularly funny cause the AK usually fares pretty poorly.