RIS recipe grain bill?

[green_giant43]

This is one style that I'm studying that I can't seem to get a hold of after reading books and a few articles online. What is a typical grain bill for this style?

From what I see, it can be
- about 60+% of your base malt (either 2 row or Maris Otter if you want a slightly more biscuit flavor)
- roasted barley (7% to 20%?)
- chocolate or black malt
- flaked barley for head retention/body
- perhaps some crystal

I just can't get a sense of the general "guidelines." Is this style just that undefined?
Just looking for a "base" that I can go off of and develop my recipe a little better.

 

[McKnuckle]

I haven't brewed this recipe, but I would:
https://www.homebrewtalk.com/showthread.php?t=238807

The grain bill of a historical RIS is not as "creative" as modern interpretations have become, with oak and flavorings and such. Originally this style was just a much stronger, or stouter, if you will, stout (itself already a stronger porter). It was literally exported to satisfy the tastes of the royalty in Czarist Russia.

For convenience, the linked recipe's grain bill is here, with percentages rounded:

82% pale
7% roasted barley
5% dark crystal (100L)
3.5% chocolate
2.5% dextrine malt

Interestingly, this is similar to a delicious regular strength (1.045 OG) stout I have on tap:

70.0% pale
7.3% roasted barley
4.0% crystal 80L <-- just a hair less than the above, and slightly lighter
2.7% Carafa II <-- another type of chocolate
7.0% flaked oats <-- extra base malt and dextrin represented in the flaked adjuncts
9.0% flaked barley