The information about socket bayonets is completely wrong. They were invented circa 1690, they were used at Waterloo and were certainly universal by 1880.
The language spoken is questionable throughout the series. There is no agreement on when the F word came into being as a swear word; the educated classes are constantly saying "you and I" when it should be "you and me"; and there is regular use of "excuse me", which is a more modern Americanism, instead of "I beg your pardon".