I watched this too. very interesting. I especially liked the .308 version; Thats the 417 correct?
The one thing I noted was the sand test. I saw a video from guns and ammo.com where teh guy crawled through the mud with an M1 (m14 type) with an OPEN chamber. Afterwards, he was able to chamber a round, but had to cycle it manually because of the crud.
I wonder how the 416 would do ina similar situation...