I don't often criticize friction writers but I do some times do the eye roll for people who should know.
Mister Brandon Webb, The M40 Marine Sniper rifle was NOT chambered in 30-06 (The Killing School, by Brandon Webb, SEAL Sniper Instructor). There are a few others but you get the point.
In Historical Non-Fiction I would like to see more detail, Mr David McCullough, (1776) please tell me about the Muskets and Pennsylvania Rifles, a bit about the pistols would be nice too.
I enjoy most, the old military gun writers, Hatcher, Edward Lewis, Whalen, to name a few, and don't forget Ingalls (brush up on your math for that one).
Oh of course we can't neglect Dr. Francis Mann's search for accuracy that would put modern bench rest shooters to shame.
Also the old early 20th century Marksmanship Manuals, we can still learn a lot from those. Who now teaches indirect fire with a rifle?
I taught machine gun schools to Alaska Natives, and others, most without a high school education. If not for Hatcher's "Machine Guns, 1917" I wouldn't have come up with how to instruct in the use of Mil's for these young soldiers, who's math skills were limited to the number of whales the government allotted for their village to strike.