So you want to build a Harlot, huh?
Good choice. Whether you’re a beginner or an expert, the Harlot is a very simple and effective pistol to build. She is a single shot, break action, derringer type .22LR pistol 
designed to be strong, safe, and reliable. Please do exercise caution during use, always obey the rules of firearm safety and be aware of the laws in your area.
Have fun, be safe, and always, ALWAYS, be free.
-BAD-CAD

PARTS LIST-
8: M3x20mm button head screws
6: M3 nuts
1: 10mm OD x 1mm wire x50mm long spring (springs as small as 8mm, or 3/8” OD are fine as long as the wire is no thinner than 1mm)
1: Rifled .22 barrel liner, 37mm long -or- 9/32 OD x .028" wall x 37mm long steel tube

TOOLS-
-Driver for your M3 screws (hex/Phillips/flat head screw driver)
-5/16 drill for .3125" OD rifled liner -or- 9/32 Drill for steel tube.
-#1 drill to chamber rifled liner
-Super glue or epoxy to hold the barrel liner in place.
-Clamp/vise/hammer and wood block to press barrel liner.
-Wire cutters to cut spring to length.
-File to shape firing pin screw to a flat point. 
-Hack saw and small round file or countersink tool to cut and deburr barrel liner.
Note: Barrel liner must be chambered with a #1 drill bit and deburred carefully with a small round file or countersink tool.

PRINT SETTINGS-
-PLA material is fine for this build, I personally prefer Esun PLA+.
-Breech Block should be printed at 99% infill, everything else should be at least: 6 walls/top/bottom, 15% infill with a 3X line multiplier.
-I recommend against printing with a brim, elephant’s foot has caused fitment issues for some during assembly. If your printer is well tuned these parts shouldn’t require post processing to assemble, tolerances have been built in.
-No supports. None. Turn them off.

LINKS FOR PARTS-
-.22 Barrel Liner: https://www.brownells.com/gunsmith-tools-supplies/barrel-tools/barrel-liners/22-caliber-rimfire-barrel-liners-prod10974.aspx
-Tube: McMaster-Carr part # 89895K617
-Tube: https://www.zoro.com/zoro-select-stainless-steel-304-tubing-932-od-x-028-wall-25-g1210/i/G1195137/?gclsrc=ds
-Spring: McMaster-Carr part # 1986K95
-Spring: https://www.amazon.com/uxcell-1mmx10mmx50mm-Stainless-Compression-Springs/dp/B076LZ86N2/ref=sr_1_1?crid=GGCQRMK5IM8T&keywords=uxcell+Compression+Spring%2C304+Stainless+Steel%2C10mm+OD%2C1mm+Wire+Size%2C50mm+Free+Length%2CSilver+Tone%2C20Pcs&qid=1643121751&sprefix=uxcell+compression+spring%2C304+stainless+steel%2C10mm+od%2C1mm+wire+size%2C50mm+free+length%2Csilver+tone%2C20pcs%2Caps%2C257&sr=8-1

PARTS KITS-
https://www.db-firearms.com/store/p/harlot-complete-parts-kit

BUILD TUTORIAL-
https://www.youtube.com/user/AscensionPWND


NOTES-
-The UFA compliant grip spacer is available in the files to make it easier for users to install the legally required 3.7oz of metal mass. Users who intend to reach that requirement by other means need not print that part. 
-Using a smoothbore tube may make this an AOW. Again, it is the user's responibility to be aware of laws in their area. I am not a lawyer, this is not legal advice.
-Please be aware of the half-cock safety feature, if you intend to store the Harlot with a round in the chamber be sure to keep the hammer at half-cock.
-Many thanks to the rest of the Black Lotus crew for the design input and testing help.
-This is a Reppringer INSPIRED build but this is my design, not a copy or remix. 
-Stay tuned for many more variants and mods!
-Please support Black Lotus Coalition on social media and consider donating to their design efforts.
-I am not liable for the misuse of this design. Code is free speech, art. It is your responsibility to build and use it responsibly.

If you like this design, please consider donating or subscribing to the Black Lotus Coalition Patreon to support future 3D2A endeavors: https://www.patreon.com/posts/62245460

UPDATES-
1/25/2022-I have added a chamber pressure blow off to the barrel which is a failsafe in case the barrel liner walks forwards or the bore is obstructed. Links, minor fitment improvements, and adjusted sights.
2/7/2022-Reinforced the latch lug on the breech block.