Many months and pesetas after its formation, the Aragonese Royal Army's Intermediate Rifle Cartridge Commission returned to the Alcochete Firing Range, new CETME-K trials rifles and made-to-spec experimental ammunition in hand. The CETME Model K was an interesting beast unto itself, though rather shorter than the Model C and designed from the ground up to both chamber the calibres being trialled, the K was in no way appreciably lighter, a concession to the physics inherent to the roller-delayed blowback action. Projections indicated not even swapping the materials for lightweight polymers and alloys would significantly reduce it, disheartening some members of the commission already, but its top ballistics consultant, Gregor Bleier, would not be deterred so easily. Bleier had been an engineer for Sauer & Sohn before the german flu, eventually finding work for a Spanish arms company under the socialist regime, where he has remained since La Provi took over. On the commission, he had largely been responsible for pushing for a 6mm option.
At Alcochete, the rounds were put through a battery of tests to assess their performance...
You CETME up to Fail
Re: You CETME up to Fail
First up was the 6x45mm entrant, Bleier's personal bid. Despite being the fattest and heaviest load of the lot, it performed admirably. It was able to consistently deliver lethal force at ranges exceeding the other two, and compared to 7.62 all three were very light and controllable, even in fully-automatic bursts. However, its trajectory was noticeably less flat than the others and its stopping power was not meaningfully greater.
It was followed by 5.6x57mm, which performed more or less exactly as the committee's critics had predicted, with pitiful reach and punch. As if to absolutely drive the point home, multiple cartridges' aluminium cases caught fire. Fortunately no injuries were had as a result of it, but this immediately disqualified it from consideration, and cast doubts on the space age materials choice.
Finally, the 5.56x45mm. At shorter ranges, it was found to be considerably more powerful than the 6mm, owing to its much higher velocity and smaller profile, but its long range performance and overall ballistics were mediocre. Although it did gain some favour with the testers for its positively compact size, being the smallest cartridge in testing and considerably smaller than the 7.62mm cartridge in service.
The new plastic formulation was found to have undesirable characteristics on impact and the necessity of a lightened projectile at all was called into question. Multiple rifles suffered failures with some of the ammunition that was evaluated, mostly from cases shearing. Further, with no workable ideas at the moment for how to lighten the rifles, any hopes for adoption are in serious jeopardy.
After much argumentation, the commission agreed to revise the cartridge designs and order a new battery of tests as well as put out an open request for novel solutions to the rifle problem. The new cartridges, which will only be in 6 and 5.56 mm, will be traditional lead bullets in full copper jackets with brass cases, though it will take time for new moulds to be created as the projectile shapes have had to be changed to account for the mass difference.
It was followed by 5.6x57mm, which performed more or less exactly as the committee's critics had predicted, with pitiful reach and punch. As if to absolutely drive the point home, multiple cartridges' aluminium cases caught fire. Fortunately no injuries were had as a result of it, but this immediately disqualified it from consideration, and cast doubts on the space age materials choice.
Finally, the 5.56x45mm. At shorter ranges, it was found to be considerably more powerful than the 6mm, owing to its much higher velocity and smaller profile, but its long range performance and overall ballistics were mediocre. Although it did gain some favour with the testers for its positively compact size, being the smallest cartridge in testing and considerably smaller than the 7.62mm cartridge in service.
The new plastic formulation was found to have undesirable characteristics on impact and the necessity of a lightened projectile at all was called into question. Multiple rifles suffered failures with some of the ammunition that was evaluated, mostly from cases shearing. Further, with no workable ideas at the moment for how to lighten the rifles, any hopes for adoption are in serious jeopardy.
After much argumentation, the commission agreed to revise the cartridge designs and order a new battery of tests as well as put out an open request for novel solutions to the rifle problem. The new cartridges, which will only be in 6 and 5.56 mm, will be traditional lead bullets in full copper jackets with brass cases, though it will take time for new moulds to be created as the projectile shapes have had to be changed to account for the mass difference.