You can definitely do it with one shotgun if you get one with removable chokes. Like gstanley up above, I went many years using a Remington 1100 for hunting everything under the sun and did shoot trap with it. I had 3 barrels for it but I didn't have Remchokes as it was an older one. Really you would only need an extra barrel if you are going to deer hunt, but even that isn't a have to.