 Finding numerous defects in this prototype ammunition (U.S. authorities later were forced to produce new ammunition for the 1907 trials), Luger had DWM pull the bullets of these cartridges and had them re-loaded with a special faster-burning powder in new brass cases.Luger brought 746 rounds of this new ammunition to the March 1907 trials with his .45 Luger pistol.Two test .45 Luger pistols, bearing serial numbers 1 and 2 are known to have been used in the 1907 tests.