Rifles have changed a LOT in 100 years, but it's been a sum of small innovations.
For example, when the Winchester 1886 was created, it was chambered in .45-70 and threw a 405 grain lead load at 1,400 ft/s for 1763 ft-lbs of energy. My modern 1886 is chambered in .45-90. If I really want it to, it'll drive a 405 grainer at 2,200 ft/s for 4350 ft-lbs - well over twice the energy. There was no one big change, but rather a host of small ones - nitro powder (and several incremental developments thereof), a .25" longer chamber, better steel, better cases, jacketed bullets. But add it all up, and you've got a totally different set of capabilities.
The same thing has happened to bolt actions. My 7mag has less felt recoil than a M1903, but it'll easily keep a bullet with better terminal performance than M1 ball supersonic for over 2000y if I want and it can deliver a reasonable chance of a hit on man sized target at a mile if the wind is calm. And that's just an off the rack hunting rifle with a scope bolted on. In WW1 they would have killed for crates of them. A whole bunch of small changes like recoil pads, good glass, adjustable parallax, down-angle mounts, magnum cases, good slow powders, and polymer tipped bullets make that possible. Add it all up, and it's a totally different gun.