It's damn close to the fastest. I have an old dead orbit sniper, the original year 1 model, with the same perks plus ambush scope for more base reload. I also got curious about this a while ago (before private matches) so I tested mine out on patrol. Was a bit of a bitch getting the enemies to line up correctly, but I got it on the 2nd attempt. It was about as fast as your video, but without pulsewave. Also, as a sidenote, I believe it can go even faster with the aura reload perk from king's fall. Say, for example, you're at warpriest. Your teammate is running stormcaller with pulsewave. Just as damage phase begins, you head over from your side, having punched an ad with war machine along the way. You start sniping the boss, then for whatever reason, you use your last shot on an ad and get a headshot kill. Boom, outlaw, spray and play, war machine, pulsewave, sniper loader and aura loader all at once. Highly unlikely scenario, but not impossible.