Noise near the shooter's ear using plastic short range training ammunition and plastic blank ammunition

This report is a delivery to Nammo Bakelittfabrikken AS. It documents that NM250 plastic short range training ammunition and NM226F1 plastic blank ammunition make less noise at the shooter’s ear than ball ammunition in caliber 5.56x45 mm NATO (NM255). We have also measured NM126 and NM134 plastic blank ammunition (7.62x51 mm NATO) relative to NM231, with the same result. We use methods defined in MIL-STD-1474D. When comparing training and blank ammunition with standard ammunition, we see that the peak pressure and the C-weighted sound exposure level is smaller for training and blank ammunition. This means that the use of such ammunition reduces the possible risk of hearing damage for the shooter.