The barrel of the mortar can be disassembled for cleaning.  This is done by removing the screw in the upper right picture.  This should NOT be done with a modern screwdriver.  They are too hard and will destroy the screw.  Use a screwdriver from a Mosin-Nagant rifle kit.  When this is done the barrel can be unscrewed from the base as seen in the photo below.

The bottom left picture shows a close-up of the threading at the base of the mortar barrel, while the photo below shows what the inside of the barrel looks like.

The traversing screw is one of the more troublesome parts of the weapon.  This is because if two of the screws on the end of the screw are not fastened correctly, the weapon will lock in place and be impossible to traverse.  If this occurs DO NOT attempt to force the traversing knob.

Instead follow the instructions below.  The problem lies with the two screws shown in the lower right picture.  They must be firmly fastened to eachother BEFORE the main screw has fully threaded itself in the larger of the two pieces.  That way the two end pieces lock together and turn within the traversing frame.  When the traversing screw jams it is because the screw has locked into the larger screw at right.

To remove the screw assembly for cleaning or to perform the adjustment mentioned, you must loosen the small screw on the traversing knob (seen above).  Then the whole assembly can be unscrewed one piece at a time.

The larger retaining screw can be seen at right.  When the weapon jams, this is the problem.  You need to firmly fasten this piece to the retaining screw BEFORE threading the traversing screw into it.  This will allow it to rotate freely in the traversing mount, rather than being locked into it.

This section focuses on the firing pin and gas vents.  The upper right photo shows the firing pin (the small bump on the center circle) when the gas ports are closed.

The two pictures below show the gas ports in the fully open position.  On three of the four sides are slots of differing lengths.  Two of these can be seen below, while the longer slot can be seen at the lower right.  The position of these change the range of the shell.

Back to M-1939 Mortar
Main Page

Back to M-1939 Mortar
In Detail Page