The H11 controversy

The UCNA always struggled to standardize. Decimalization was still underway at the time, and it was surrounded by several distinct, and mutually incompatible, customary measuring systems: Anglo-Scottish to its north, an Ibero-Baltic blend down south, and French scatterings in the Caribbean (and its own borders.)

Matters came to a head, however, in 1893, when the UCNA finally phased out its long-serving .49-94 for something altogether new. It's still causing headaches in several continents today, where it's commonly known as the H11 Controversy.

Background to the H11 Controversy

The UCNA was quite happy to adopt a modern, smokeless 7mm cartridge, and started assembling them at the arsenals in Port-Royal and Nova Toleto. It wasn't until they were first issued together, however, that the Army discovered a serious problem: the two armories had interpreted "7mm" in two different ways. Nova Toleto had measured 7mm from the grooves (producing a .284" rifle); Port-Royal, however, had measured it from the lands, resulting in a .276" rifle.

These two calibers were not, in any way, interchangeable. A Toleto gun loaded with Port-Royal ammunition would have inexplicably bad accuracy, and no amount of adjusting sights could make it better. A Port-Royal gun chambering Toleto bullets, meanwhile, stood a good chance of exploding.

• Port-Royal was a significant producer of ammunition; they had a fair supply of it ready to go, and it was already being distributed.
• Nova Toleto, meanwhile, had the moral high ground: the original plan was for a .284" musket. Port-Royal had screwed up; the error was theirs, and theirs alone. Their stuff, therefore, had to go.

Production was officially halted, and Yusuf ordered Port-Royal to start producing smokeless loads for the .49-94 (which, at least, was standard.) Port-Royal did so, releasing it as the H12. Gun production, however, did not halt.

The final conclusion was, in the end, one that pleased nobody. The H11, after so much time and trouble, was simply not adopted. Nova Toleto's standard was declared to be correct: .276" was abolished. To prevent any future headaches, the UCNA's current nomenclature was established: all cartridges were to be named based on the measurement from the lands. (Thus, Nova Toleto's beloved 7mm transformed into the 7.21mm overnight.) Port-Royal's rifles were rebarreled and resighted.

Most importantly of all, almost everything H11-related - cases of Port-Royal ammunition, one-off guns, test pieces - were withdrawn from service and sold overseas.

The headache goes global

A major consideration was that, despite being designed by Port-Royal and such, the H11 had never been officially adopted, and thus wasn't a "military" caliber. It certainly performed like one, though - it was flat-shooting and sizzling hot by the standards of the day.

And late in 1895, an assortment of H11 weapons wound up in the hands of Mahdists, who decided to try these things out. By the time they ran out of "magic bullets," the Chergui had bloodied the Spanish and seriously shaken their morale - Spain had never been on the wrong end of the tech curve before.

Spain (which was still smokeless at the time) needed to modernize, and fast. (Portugal wasn't under quite as much pressure, but took the opportunity to modernize too.) Their problem was that they perpetuated the problem:

• Portugal adopted a rimless loading of the H11, which had already established the name "7mm." (They even took the opportunity to buy some molds, dies and machining parts from the Toleto armory.)
• The Spanish Crown, meanwhile, had adopted the UCNA's own H13 cartridge, rim and all... and following Old World conventions, they'd also labeled it "7mm." (At least one theory holds that the Crown of All Spains was hoping the Mahdists would wreck their guns with it.)

The problem had passed out of the UCNA's hands and into Europe's. Once again, both calibers were being circulated. This time, however, the problem was orders of magnitude larger; the two calibers were being adopted globally.

The Old World's solution? Call them both "7mm," and distinguish between "H11" and "H13." It worked IRL, after all.