Ruger Mini-14 - I used to hunt rabbits and ground hogs with this and use it for home defense. The accuracy is very poor past 50 meters
Is that you or the rifle?
They're not competition guns but a decent example is certainly capable of decent shooting past 50 meters.
Try putting an accu-strut on the rifle. Most early Minis suffer from barrel whip due to the thin barrel profile. The barrel gets hot and then starts vertical stringing. If you can put the first few shots on target and then they start walking, this is your issue and a strut should help. You might also try re-torquing the gas block screws, this has been known to shrink groups also. Check out the Perfect Union forums for everything Mini.
As to the OP, seems to me your missing a quality lever action. Look into a Marlin 336 in .30 WCF. Ammo isn't super expensive and is readily available anywhere. The .30 WCF is good for anything up to and including black bear within reasonable range. It's also not a bad plinker if you reload.
If a bolt gun is desired I would second the 6.5x55 Swedish Mauser although ammo can be hard to come by at times. I reload so keeping mine fed isn't really an issue. Winchester doesn't currently list the 6.5x55 on it's web site so you might have to have to go to a Tikka or CZ (check out the CZ 550 FS).