I think RU 77s have always been investment casting? No "older" or "newer".....
I have two RU77 Tang models that you could not pry me from. Both are blued/wood, tho for my uses I would prefer SS and plastic... I'm hard on rifles.
One is a .338WM, self worked on, after purchase, 2nd hand at fair market value. Didn't work very well factory standard. Glass bedded, free floated, factory trig tuned to 3.25 or so poundage. As light as I could get it safely. Stick-on rubber cheek piece added to accomodate my long neck. I installed a .260 base and .260 blade front, silver soldered on, in case the scope goes tits. Rear sight is a V filed into the higher integral scope base. I always disliked those Ruger high sights. This one is low profile, zeroed at 100 with 250 gr loads.
The other RU77 Tang (.30-06) is a "deplorable" picked up for $80. Chopped the muzzle bulge out to 17 inch bbl length, glass-bedded /free floated the stock, worked factory trigger down to about 3#., refinished water damaged stock, chopped that fore and aft , and slimmed forend to make it propotion to eye-appealing '"for the wife". Mostly, I use it, with a 1" slip on recoil pad over the Decelerator pad (which the .338 also sports, to my LOP).
Basically, I anticipated Ruger's "carbine" models by about 10 years...
And, by the way- both shoot 1.25 MOA or better with factory loads, and mo-better with certain fire-formed handloads. The .338 prefers shoulder headspacing to rim.
