Walther started the commercial production of the P5 at sn: 001001 and following pistols were numbered consecutively. The pistols produced for the Dutch police had their own serial range range (50,000 – 100,000)

In 1987, the commercial production reached the 50,000 and a few pistols were produced in the 50,000 range before Walther staff realized that these serial numbers were already used for the Dutch police.

So at that moment two P5s with the exact serial numbers existed, which is ofcourse undesired. Walther didn’t want to destroy the guns and therefore decided to put a letter “D” behind the serial number. The “D” probably stands for the German word “Doppel”, which translates to “Double”. The highest serial number known of a D-series pistol is #050209, indicating hat around 209 pistols of the D-series were made.

Two variation of the D-serie are known:

" Single D " variation:

This variation has the letter D stamped only on the frame. The majority of the D-series pistols areof this variation.