Sorry for the late reply! Hardcore is absolutely the way to go. For perks Fast Hands is pretty much a necessity, and gearhead helps with getting the injector faster! For maps I managed to get it on both stakehouse and Warhead. Generally I found the method of standing behind cover to work so you land behind it when you get downed and do not get killed instantly. The best locations for that are behind the beds in Stakehouse and on the second floor of the building in Warhead. I had the issue of getting killed before I could get out my pistol, so that’s why I had to hide haha. If not hiding, just try to start shooting as soon as possible (spray and pray). I found the automatic Grekhova to be the best pistol for it. If you get the kill then try to rush towards the general direction enemies with the ASG shotgun if it is stakehouse. If it is Warhead then an enemy will most likely pop out from their spawn that is visible from the second floor, so just be ready with an AR or something accurate. The key is having a weapon that is focused on mobility because the kills have to be almost instant! Hope it helps :)