I noticed a lot of those weapons got nerfed when my friends and I met this survivor who just spawned. He was being chased by zombies so we all shot them off him and went to go bandage him and what not. I went up to him and as I finished bandaging him, he took the loving FAL out of my coyote backpack and equipped it (luckily all the ammo for it was in my immediate inventory so he was no threat). I lit him up with like 8 shots of my glock and it did nothing, so my whole team starting firing at him with all their firepower lol.