The .270 was first offered in 1925 in the Winchester Model 54. It is basically a .30-06 cartridge with the neck squeezed down to accept a .277" diameter bullet. The advantage of the .270 is that it will shoot a (lighter) bullet to a higher velocity than the .30-06. The .270 was the favorite of the late, great Jack O'Connor, who hunted extensively in North and South America and in Africa and wrote some of the best hunting and shooting articles and books of his era.
The Model 77 Ruger was developed by William B. Ruger, who founded his gun company in the late 1940s. Originally concentrating on handguns, Ruger branched out into rifles in the 1960s. His taste in rifles closely followed the "classic" stocks and handling characteristics, as opposed to more radical and decorative weapons (such as those of Roy Weatherby.)
Your Ruger was made in 1976, as the legend on the barrel implies -- 200 years after the signing of the Declaration of Independence. All Ruger firearms made that year had this legend -- I have a Ruger Blackhawk revolver with the same legend.
You have a superb hunting rifle -- just about ideal for deer and similar-sized game.
