I bought this gun at the end of hunting season from a neighbor. I know it is Winchester 1300 12gage with the 22inch barrel for sure. I am pretty sure it is the Win 1300 Black Shadow Deer. I am not 100% on the model but how do I find out and what is the difference b/t the Black Shadow Deer and the Black Shadow Deer Combo? Also he sold it to me with two different chokes. I have only shot slugs through the gun and it shoots fine. He said he shot slugs and bird shot through it and you dont have to change the barrel. And if you change the choke it just makes a tighter group with the bird shot or a wider group depending on which choke is in. Is this guy bull****ting me? Will it be fine to shoot slug and bird shot through the same barrel? And besides just changing chokes and looking at the group on the target is there any other way to know which choke is which? They look very much a like. I've got a few different guns here and there in my day and I have always just posted up with an old Spesco single shot I got from my uncle when I was younger and now I would like to know more about the sport and the guns so if you guys could help me out that would be great.