Longshot Build Kit

Longshot Build Kit Overview

The Longshot Build Kit is the extended-barrel variant of the Harlot platform. Same proven single-shot, break-action .22LR design. Same fire control group. Just stretched to a 3″ barrel for improved accuracy and a sleeker profile. If you’ve built a Harlot before, you already know the platform. If this is your first 3D printed firearm, the Longshot Build Kit gives you everything you need to get started.

The Longshot Build Kit includes the complete hardware package: 3″ rifled steel barrel liner (pre-chambered), M3 hardware, hammer spring, latch spring, breech dime (pre-drilled), ejector rod, and firing pin screw. Download the STL files from DEFCAD, print your frame and components in PLA+, and assemble. No machining required.

Where the standard Harlot uses a 1.5″ or 2″ barrel, the Longshot Build Kit stretches that to 3 inches for better velocity and tighter groups at distance. Multiple barrel configurations are available in the file package, including options for optics mounting (RMR, Docter, Shield, C-More, Glock MOS) and Picatinny rails (Short 1913, Long 1913). Same Harlot reliability, more flexibility for precision-minded builds.

What’s Included in the Longshot Build Kit

3″ Rifled Barrel Liner (Pre-Chambered)
Steel .22LR barrel liner, 3 inches long, already chambered and ready to install. No drilling or reaming required. Epoxy into your printed barrel shroud and you’re done.

Pre-Drilled Breech Dime
Modified dime (OD 17.9mm) with firing pin hole already drilled. The dime breech design (Breech V3) has been tested beyond 400 rounds. Epoxy into the breech block with the chamfered side facing the chamber.

M3 Hardware Set
Button head hex drive screws (M3 x 20), steel hex nuts, and extras. Everything you need to assemble the frame, secure the barrel latch, and complete the build.

Firing Pin Screw
M3 x 20mm screw, chisel-tipped. Threads into the hammer and strikes the rim through the breech dime. Pre-shaped and ready to install.

Springs
Hammer spring (compression) and latch spring included. Cut to length per the assembly drawing if needed.

Ejector Rod
3 x 63mm acetal rod for case ejection. Slides through the breech block to push spent casings out of the chamber.

What Makes the Longshot Build Kit Different

3″ Barrel for Improved Accuracy
The Longshot Build Kit doubles the barrel length compared to the original Harlot. More barrel means better velocity, more consistent ballistics, and tighter groups. The design notes “+5 accuracy” over shorter variants, and builders report noticeably improved performance at 25+ yards.

8 Barrel Configurations
The Longshot Build Kit file package includes eight barrel options: Clean (iron sights only), Short 1913 rail, Long 1913 rail, RMR Cut, Glock MOS, C-More Cut, Docter Cut, and Shield Cut. Mount a red dot, add a rail for accessories, or keep it simple. Your choice.

Dime Breech Design (V3)
The Longshot Build Kit includes a pre-drilled steel dime for the Breech V3 design. This is the most durable breech option in the Harlets family, tested beyond 400 rounds. The steel dime handles the chamber pressure while the printed breech block handles the structure.

Cross-Compatible with Harlets Family
The Longshot Build Kit uses the same grip spacers and side panels as the Harlot V2, Quiet Girl, Shizukana, and Artillery Boi. If you’ve already printed custom stippled panels or a UFA-compliant grip spacer for another Harlet, they’ll work here too.

576 Possible Configurations
Between barrel options (8), breech options (2), trigger options (2), hammer options (2), and clipazine/brace options (9), the Longshot Build Kit supports 576 unique configurations. Start with the default build, then customize as you learn the platform.