I hunt whitetail in Iowa - a shotgun only state. My gun is a 12ga Remington 1100 Wingmaster with a bead site. Typically I shoot 2-3/4" rifled slugs (Winchester SuperX.) Basically it's a pheasant gun; not exactly ideal for whitetail. It was handed down from my grandfather and I've hunted with it 28 years. I've been considering and researching a new gun for at least the last 10 years, but I normally hit what I aim at: up to 80 yards consitently and when I miss it probably isn't the gun's fault. Four years ago I dropped a real nice 8-point doe (yes, an antlered doe!) at 120 yards with one shot. This year I hit a buck at 150 yards, but shot 7 times. So I have kept with my old gun figuring if it isn't broke, don't fix it.

It's time for a new gun.
My gun has always hated cold weather, not ejecting the shells correctly. This year was extremely bad. We had freezing rain and sleet the first day. The second day was was around 10 degrees and my gun wouldn't eject a single shell by itself. By the end of the day I had to warm the gun in the truck to get the shells out of the gun at all! It's time for a new gun. So here's what I've learned about shotguns for deer over the last 28 years of hunting and 10 years of reseach.

12 ga vs. 20 ga.
I've always prefered a 12 Gauge. We hunt the South side of a river that runs along the IA/MN border. We group hunt with anywhere from 16 to 22 hunters (legal in Iowa) - meaning we have walkers who make their way through the woods and push deer to standers on the the other side. Both walkers and standers are often shooting at running deer and "knock-down power" becomes important. In some instances, if a wounded deer makes it across the river we have no good way of getting to it and the deer could be safely in Minnesota where we can not hunt. We had 9 kids between 13 and 16 years old who hunted this year, and most of them shoot 20 gauges. 8 of the 9 kids shot at least one deer, however we never got a wounded 10 point buck who made his way across the river. A 13 year-old hunter shot the deer with his 20 ga. The deer dropped and stayed down for almost a minute before getting back up and making it's way across the river. If it had been shot with a 12 ga, it might have stayed down... or at least wounded the deer enough to let us get a second shot.

Scopes
I had a side-mounted scope on my gun for 3 or 4 years, but removed it about 10 years ago. Almost everyone I know (including me) who has a scope on their shotgun has split their nose open at least once. In the excitement of moment they either didn't get their gun shouldered correctly, were shooting at an akward angle, or simply didn't have enough eye relief. Eye relief is something important to consider when looking at a scope for your shotgun!

I will probably get a scope on my new gun. I'm looking at an inexpensive red-dot scope. They are pretty short and have a lot of eye relief. A 2X is about all you need and allows you to pick up a moving target easily. I will probably get a gun with a cantileved mount for the scope - though it raises the line of sight by an inch or more.

Barrels
I certainly want a rifled barrel. From what I've read; the most important thing is to shoot several brands of shells through your gun to find out which bullets perform the best. (one Remington 870 might shoot a tight pattern with a particular brand, and the exact same gun might shoot a different brand of shells better.) This means $$$ ...at $15 to $20 for a 5-pack of sabots, I realize that I will likely spend more than $100 on bullets just to find out which brand shoot the most accurately through my gun!

I also like a shorter barrel. Again, because I am often shooting at moving deer, a shorter barrel is easier to swing into place if you are in thick cover or even just standing behind a tree. It's also easier to carry if you are the one walking through the woods .

Bullets
I haven't decided whether or not to stay with 2-3/4" rounds or move up to a 3" magnum. One thing I've read is that higher velocity shells require a tighter twist in your barrel rifling: slugs in the 1200 to 1500 fps range work best from a slower twist rate such as 1 in 34 inches. Faster 1900 to 2000 fps slugs perform better through a 1-in-30 barrel. My plan is to test ammunition with a velocity that matches whatever barrel I end up with, so that will probably determine whether I shoot 2-3/4" shells or something longer. As for the brand - I'll just have to do some testing.

Conclusion
Right now I'm looking at a used Remmington 870 (12 ga) with a new 20" hastings rifled barrel with a cantelievered mount for a red-dot scope.