There are "arguably" huge advancements/progress made with regard to guns made since 1906. Not the least of which would include.
specific needs guns (varmint, dangerous game, extreme range)
safety (better materials, better engineering, better testing)
stock materials (many more options to fit the need)
and of course ammo including
powders (non-corrosive, better lot to lot consistency, more varieties)
bullets (game specific, VLD, varmint, premium)
optics (better quality, more durable, higher magnification, variables)
Although they may not have the same historical/sentimental value I believe newer guns are much more accurate and consistent.