Along with his Gate series, Takumi Yanai put out another novel. It’s called Hyoufuu no Kolkkaa: Yuki no Yousei to Shiroi Shinigami. [Icewind Kolkkaa: The Snowfairy and the White Deathbringer-god]. It’s set in Finland during the Winter War, and brings Kolkkaa (a fictional girl sniper) together with Simo Hayha, the real-life guy whom they called “The White Death.” Basically it’s the story of Kolkkaa growing up and becoming a better sniper, and then having to face two Soviet female snipers.
I don’t know if there’s any sf/f content in this one, or if it’s just historical fiction. But other than that, it sounds very Baen-ish.