The 527 is a micro Mauser for the smaller shorter cartridges such as .22 Hornet through the .223 and 7.62x39. It has a detachable single stack magazine that hangs down in front of the trigger guard and does not make for the easiest carrying as it is right about the balance point. I have two, one in .22 Hornet and the other in 6.5 Grendel and aside from that one fault love them. The cartridges offered in it are all mild recoiling, especially off a bench for target shooting. The 557 is a larger longer action, I know is available in calibers up to at least the 30-06, which will make for a harder recoiling rifle.
They do make the 527 in a varmint and a thumbhole model. For what you are suggesting I would probably go for the varmint model in somethng like .223 or 6.5 Grendel, and think I would go the Grendel route, ammo a bit more expensive, but if you want to get into some longer range shooting it is more capable.
Scopes, I tend to like the mid grade Leupold series now such as the VX 3 series, probably in a 6-24x for the range you are talking about. get one with side focus and target turrets. There are a lot of good scopes out there, best bet is not to go low dollar but get a quality scope. There are a lot you read about that are also a lot more expensive.