The M 16 version added a central barrel ring and cutouts on the side of the carriage. Rotation within the barrel was improved, greatly increasing accuracy. It weighed an extra 20 kilograms (44 lb), but had a maximum range of 1,080 metres (1,180 yd). Its transport cart was also improved.
The first batch of 100 mortars was ordered in May 1915 and a second batch in spring 1916, but deliveries were slow; only 88 of the second batch could be sent to the front by May 1916. A third batch of 300 was ordered in November 1916, but production was such that only 30 had been delivered by the spring of 1917.