A Spiral-RFQ (Radio-Frequency Quadrupole Accelerator) has been built and operated with Ar + beams up to 8 mA. The aim of the experiment was the test of the RFQ for the High-Current Injector (HSI), which is planned at GSI to fill the Heavy Ion Synchrotron (SIS) up to its space charge limit. This Spiral-RFQ, a prototype for the HSI-RFQ, covers the crucial matching and bunching section of the electrodes. It is capable to produce ion beams of high brilliance, thus being a prototype for an implanter for heavy singly-charged metallic ions. The results of recent beam experiments with Ar + will be presented.