Forgot about this method. Man I've been coveting the MKII version of the corruption since MKIIs were released. Not worth using the regular variant IMO - would rather use the one with jackpot perk (10% score) and harline for UAV spam.
I would still use the MKI Corruption over any other Volk variant. For me being 17th Prestige and having the 30% XP boost for MKII ARs, that's still a 1.8 XP multiplier for kills with it. Since I've already gotten weapon Black Sky, Rig Black Sky, and all the optic challenges, the only thing left I currently have to grind for is MP30 so that extra 50 XP on top of the already 30% XP increase helps a lot. Sadly I wasn't able to take full advantage of the week of Double XP.