I wanted to reply but the thought escaped my mind.
You can take a lot of what Ian says scholarly as fact, especially when it comes to his books as I am 90 percent sure some of them come from knowledge he's garnered from other people, particularly people who are less likely to be strictly biased like Karl.
At the same time, he can be wrong. Particularly in the case of the Forward assist. Though I do have to say I'm surprised he's not aware of the TECCOM trials.
The fault lies where I believe he is absolutely fucking stupid in terms of how things work "field wise." His video on drum mag reliability spouting about how they're atrocious when there have been great strides technologically to make them run better, and more consistently, to the point the Marines are testing them with the M27 IAR.
And if I remember CORRECTLY, they (As in Karl and Ian) even perpetrated the myth that you couldn't fire a lever-action while prone when there are a plethora of videos proving otherwise