[1] He submitted a rifle to the competition organised by the British government for a replacement for their existing Snider–Enfield service weapon.

In 1872 he was appointed "gun and rifle manufacturer to His Royal Highness the Prince of Wales".

In 1873, one of his double rifles was specially made by Henry for Queen Victoria in 1873 and presented it to her personal servant John Brown for Christmas that year.

The "extremely rare" Royal .450 double-barrelled hammer rifle was on public display for the first time from June to November 2019 in the National Museum of Scotland's Wild and Majestic: Romantic Visions of Scotland exhibition.

When Alexander Henry died, he left the business to Alick and John, but they sold it within a couple of months, beginning the slow decline of the "brand".