For some reason I've heard red on black venom lack - red on yellow kill a fellow, basically the same thing. Probably multiple versions out there, the main thing is to know the difference!
Many many years ago we killed what we believe was a Bull snake, young and trigger happy. Anyway it was 7ft 2 in. Going to try to find the old photos to see what you all think, may take a while to find. As far as rattle snakes, killed around 75-100 on the ranch in past years, just by accident. Saved most rattles and did a 5ft 2' skin myself with a cedar bord, glued most of thd bigger ones on it. Conversation stater, plus looks cool on the wall.