Calibers of the UCNA

The Muslim world gave rise to lots of guns (they introduced gunpowder weaponry to Europe), but not to many cartridges. The united case-charge-ball assembly that we call the cartridge was a product of the Industrial Revolution even if the idea was much earlier, and by that time the Muslim world was lagging far enough behind that it was importing, rather than introducing, military technology. (There are some cartridges that were big - Egyptian Remington, for instance - but even then, there's no evidence that the Egyptian Remington was designed by Egyptians rather than Remington ballisticians on contract.)

This is a problem for me, because in the end this story is about Islam. And for the part of its history that I know the most about, there is a major Muslim state that's got enough resources and vision to seriously develop their own guns during the cartridge era. This post exists because it's where GURPS intersects with sloth - and because I sweat gun porn in general, I'm going to sort out some issues here.

Caliber nomenclature

The UCNA's black-powder calibers all postdate Yusuf I (who, in fairness, was a rocketry guy.)

• Moorish calibers are underbore. The UCNA had a few standards going, and didn't measure them all the same way. The continental UCNA generally named its calibers using customary measurements, which were a bit smaller than the English ones (a Sevillan inch is 23.27mm.)
• Interchangeability was a critical issue
• Moorish bullets are (sometimes) .006" overbore. IRL, most modern calibers .008" over nominal bore size to account for rifling, but it's arbitrary, and in the UCNA the standard grooved rifling was usually a hair shallower.

Cartridges standardized on a common nomenclature, based on its caliber and the Hijri year of formal adoption. The .49-94, for instance, was a Moorish .488" (.446") ball, issued in 1294 (1974.)

• Unlike IRL, the last two digits of H-numbers do not refer to the grains of propellant. Don't try to load these at home.

The UCNA decimalized under the later Weak Caliphs.

• H-numbers: Service cartridges received a standard naming system, the H-numbers. This was based on the black-powder naming conventions; the number in "H-number" is the year of adoption.
• In the UCNA (as per IRL), different companies have proprietary loadings of the same cartridge. Most of these indicate compatibility and interchangeability by the H-number of the case.
• H11 vs. H13: The UCNA contributed an enormous tangle to global gun nomenclatures in the transition to smokeless, when communication errors led to two different "H11" cartridges being produced: one based on ball measurement (what we'd call 7mm), the other on bore measurement (what we'd call .270.) It took the better part of a year to sort it out, after which the UCNA reformed its naming scheme, made the ball-sized cartridge official as the H13, and dumped the rest on the market.
• Because Old World naming conventions do not follow New World ones, this produced no end of confusion: the H11 and H13 were both referred to as "7mm," despite being very not interchangeable. It's Andalusada's equivalent to 8mm Mauser with its non-interchangeable J and JS loadings.
• Ever since the H11 controversy, the UCNA's officially measured all metric calibers by the bore, not the ball.

Calibers of the UCNA

So what does this mean in practice? Here's some basic details. 

".49-94": The .49-94 was a .44-77 Sharps clone. It's rare that I name-check things this specifically, but in most respects - overall length, rim diameter, and ballistics - the .49-94 is probably only a shoulder angle or so from being interchangeable. It was the UCNA's last and longest-serving black cartridge, and because there's a huge diversity of guns for it, it still sees use into the present day, much like the .45-70 IRL.

• A big part of that staying power is because the .49-94 was also first universal cartridge; prior to 1874, most of Moorish Caribby standardized with Cuba, not the mainland army. By the time it was phased out, even they'd come around to it.
• Caribbean cartridges, therefore, are a family of their own, and merit a post of their own.
• Blackpowder military cartridges IRL were all fairly similar, so why .44-77 Sharps specifically? Case dimensions. When the UCNA went smokeless, the criteria for its new cartridge were based on the .49-94.

.488 H12: a smokeless "clean" loading of the .49-94. It uses an identical case; the H-number is mostly to distinguish it as official (and unsafe for use in older guns.)

• H12 was meant to phase out the blackpowder .49-94 without reducing the overall war-readiness of the UCNA (which was, remember, having a standards war at this time.)
• Because the Militia Code hasn't been updated, any man in good standing has the legal right to buy a single-shot H12 rifle. (Conversions for these are very popular.)

7.22mm H13 Taha: The winning side of the H11 Controversy was officialized as the H13 Taha. It established Regency-era naming conventions (absolute bullet-based measurements), and the case remains in use today.

• The H13 case is a rimmed case, which has affected a lot of Andalusian gun designs down the supply chain.
• The H13 was a round-nosed bullet. To indicate compatibility, the modern spitzer ball is designated the H13/29.

This is a stub. It will be expanded upon.