These cartridges have been handloaded at the Polígono de Experiencias de Carabanchel, the Spanish Army proving ground, for testing helmets from spanish manufacturers, according to Nato Stanag 2920.
Available primed cases are used (these are 7,62x51 SB 80).
The casemouth crimp applied to these specimens is too heavy, in my opinion, as the sabots are deformed. This would cause chambering problems.
The fragment simulator to be used with a sabot in 7,62 mm barrels is a simple steel cylinder with beveled tip, as seen in the photographs. The fragment simulator for 5,56 mm barrels has a driving band at the base, as it is intended for engaging the barrel rifling.