I've been trying to get this written as a draft, but have finally given up and will just be putting this out in parts.
Let me preface this with personally I think every house should have at least one long gun.
This does come into the obvious choice problem. Which one, and this comes into use, and capabilities in the factors to determine this.
Caliber, action, capacity and a whole lot more; all those play into uses and capabilities.
There is no one longgun for all uses and capabilities. That's something I realized early on, and it was a eye opener in a way.
I'm just going to go through my path, and my reasons for picking my longgun.
I personally struggled with this choice for years, my capabilities are limited due to some physical limitations of eye sight and nerve damage.
So right off the bat I knew my max range would be around 100 yards, without a scope, which I don't like on a rifle anyways.
I wanted a longgun that could take being out in the muck for a bit without being rendered useless.
I also wanted something at least .30caliber.
Capacity was kinda not a big issue for me, but I did want more then 5 shot capacity.
What I wanted it for was home defense, possible survival/hunting longgun, and battle rifle.
Those are my specs, and they evolved as I searched into that current list. These may change, depending on life.
First range, my range is limited because of my poor eyesight, and a shake because of nerve damage in my arms that makes me shake and twitch.
I cannot see really anything past 100 yards even with my glasses, general shapes and colors is the best I can see. After shooting a bit with a scope on some longguns I realized my eyes have problems focusing after initial shots to do follow up shots quickly, it can take up to 10 seconds(this found out by my doing the " 1 Mississippi count" way of finding out the amount of time) for my eyes to refocus on the scope image. I'm not sure why this happens but it does and its something I must take into account.
So ironsights are what I decided on, and they are a bit more durable then scopes. Right there I hit my first limiter, and realised sniper I am not.
Second was durability, this at first had me looking at bolt actions, but I found those limited to prone and supported shooting for quick follow up shots, and so I dropped that idea. Add in my lefthanded longgun shooting and the available models were thin. So semi-auto, lever-action, and pump-action;were left. I for years fought lever and pump actions, thinking them far to slow, until I realized that was my own capabilities were lacking and not a true problem of the actions in what I wanted it for, and most semi-autos also were not really lefty friendly. This is were I got stuck for a long time until I worked out other specs.
So that's part 1.