Can you get the buffalo rifle in red dead redemption undead nightmare?

In Red Dead Redemption there are a few ways to obtain the buffalo rifle. If you're talking about online, it can be obtain by reaching level five hunting. I'm not sure if this is entirely true but it's what I've heard. If you're talking about single player, you may obtain it by once again reaching level five in hunting and going to Armadillo to purchase it. Once again i do not have the buffalo rifle yet so i do not know 100

He is correct, you can also get it at any gun shop.