Book 2 in the Soldier of the Queen Series, by Griff Hosker.
The British Army at the end of the nineteenth century was not a fair place. Despite the reforms, a bad officer could still ruin men's lives and Jack Roberts discovers that despite being a hero of Rorke's Drift, that means nothing when a superior has influence. He becomes a soldier serving in the Egyptian campaign where he learns not only new skills but how to deal with the new responsibility fatherhood brings.
Throughout it all one thing is constant, he is a soldier of the queen, a redcoat with a rifle.