Krag
Thats a very pretty Krag, and I wouldn't fiddle with it. The Krag action is a very slick action, very smooth and that contributed to a lot of customised Krags. The bad news is they are not a real strong action, do not be tempted to soup your 30-40 Krag up to 30-06 or .308 ballistic's. The rifle wasn't made for it and a lot of old timers found this out the hard way, it not the strongest action, its not an old 98 Mauser and never will be.
30-30 ballistics hardly. Its closest contemporary cartridge to compare it to would be the 300 Savage or a 303 British, although the 30-40 wins by a small margin against the Savage and equals the British Service round. Without hot roding it, in a sound servicable Krag that can be safely loaded with 165gr bullets at 2450-2500 FPS, or 180gr @ 2400. Which makes it more than adequate for all game in the continental US. It would be not be my first choice of rifles in Alaska, when dealing with big bears in close cover, but was once a very popular round with the old sodbusters. I think at one time a Krag could be bought for $7-10 which put a lot of old Krags in civilian hands. There is a saying that any round that was adopted by the US Army, will maintain a certain popularity, and I think the 30-40 is no exception to this. Not as popular today as it was 40 years ago, the round is listed in all current loading manuals, and Winchester still sells factory ammo for it, in 180gr Powerpoints.
Your rifle in no way looks abused, but if you are in doubt have a gunsmith check the headspace ( a safety precaution I like to do in older rifles )