Just because you specifically have not seem videos of people leaning and shooting from cover and concealment with a rifle does no not mean it doesn't happen, and has a matter of a fact being able to do so increases your survivability in a gun fight, it is absolutely necessary and is taught to those who carry a gun professionally, IE military and law enforcement.
@xMotherloadxUntrained idiot here, I can crawl while completely prone with a full backpack on my back. We had to do that as some sort of nonsense training exercise in the scouts. Forty pound backpack, chest on the ground, slither like a snake. Why can't a specialist do the same, right?
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