I am a big fan of the M-1 Carbine. Though, my "rough gun" is an SKS. It is accurate enough to take down game and is very reliable. They are cheap to buy to which means if it breaks, gets lost or stolen, you are not out much.
It's accuracy is not on par with an AR-15 or even a Mini-14, but it can still reach out and touch with ease out to 150 yards. Which is more than good enough for everyday use. The rifle is damn near indestructible, mine has over 5,000 rounds though it and has gone boom every time I needed it to without fail. They are easy to use, easy to clean and easy to fix if they do ever break.
There are detachable 20, 30 and even 45 round magazines for them. There are also lots of stock and optic options, though I have found that mine is just fine bone stock. The sights work well and the non-detachable 10 round magazine works just fine. I keep it in the back of my truck when I am out in the woods, I keep a few 10 round striper clips with it and it works just fine.
You can buy a cheap Yugo and trick it out for not a whole lot of money. With compensator's and better optics you can tighten up the groupings pretty nice. I have a modded SKS and while they are fun and cheap to trick out they kind of defeat the purpose of a field gun in my own opinion.
My Norinco "Rough gun"

My modded Yugo. The rifle was about 100$ and I have about 350-400$ worth of parts in it and on it.

