1775 5 Kopeks For Grading Opinion

I'd say AU details; it has a really uneven strike, and some areas look like serious environmental damage, but there's just about no actual wear that I can see.

I don't think it's MS (though this wouldn't surprise me), but it's probably at least AU.

I agree with all the above comments. If those rough areas and the pale spots on the monogram are environmental damage, I also guess a details grade. The St George (or whatever it is) in the center is very sharp, which fits with j1m's comment on AU.

Pair of nice coins, @keith (especially since I saw the selling price of the 1773

Now I understand your confusion.

To me the 1773 has better eye appeal, despite the slightly lower grade from PCGS. Presumably they felt the 1775 had experienced less post-mint wear and what we are seeing reflects something like an advanced state of Die Deterioration (or some other quality issue in the coining process)?
I would also point out that these two coins were probably not on the same submission, so maybe different graders also comes into play?

Regardless, it fits with my experiences with grades of coins from this era not necessarily correlating with the eye appeal in these grade ranges (AU to low MS).