[Future Snake Eater]

Most military arms can go 500 rounds or so (wiggle room) back to back before heat becomes a problem.

Plus he had multiple rifles, so if a barrel did get too hot, he could drop it and grab another one.

[Lionheartusa1]

I saw 860 rounds go thru an AR 15 as fast as you could change 40 rnd. mags before it failed due to a barrel split at the gas block . I was a purposed test .