***Pocket PP

*Dangerously small pocket pistol*

All parts should be printed flat on the side and with 100 infill.
Barrel should be printed upright with narrower center hole on the bottom.
8mm OD x 6mm ID hydraulic tube/seamless pipe is best suited for barrel inserts, though .22 barrel liner can be used too.

You'll need:

-6x 3mm screws/nuts
-One 4mm screw at least 40mm long / nut / at least 8x washers
-8-12 mm spring
-any smaller spring for the trigger
-3-5 mm spring for locking mechanism
-Random junk from your garage

Striker is made by gluing a 3mm id nut inside the front of the bolt and screwing in a 3mm screw until it's tight enough.
This screw head sholuld be cut off and the screw itself trimmed so it only protrudes about 2mm from the breech plate,
then removed and only inserted after the bolt and the spring is already in place. It's a good idea to smoothen out top of of the screw to v or u shape with slightly flat top.
At the back of the bolt, insert a few washers that you found uDner the workbench until it's sufficiently heavy.

Barrel is attached with 4mm screw - it's head should protrude from the breech plate accompanied by a washer. Couple of washers and a nut go inside the barrel rotation center. 
Apply loctite before screwing everything tight, but not too tigh, barrel needs to be easily turnable by hand. Put a little bit of grease around moving parts.