Arrow Breech, Crosman 13xx & 22xx

thingiverse

Breech for shooting arrows from Crosman 13xx and 22xx air pistols and rifles features a Picatinny rail and dovetail for mounting optics or using the built-in sighting tube. It is ambidextrous, linear-pull, side bolt handles, utilizing the two screws that originally secured the factory polymer breech. The optional barrel band adds stability to CO2 and PCP guns, requiring removal of the arm and piston assembly and trimming of the pump handle for clearance on 13xx guns. The band is captured between the compression fitting and compression nut and slips over the front screw and tab of the pistol grip assembly. Upgraded valve and transfer port bushing are recommended. The arrow barrel assembly includes: 6mm OD x 4mm ID metal tubing, 300mm length can be used by chucking it in a lathe or drill press to turn down or sand the outer surface to fit the inside diameter of the arrows. The arrow should slip over barrel with minimal resistance yet not slide off when gun is pointed downward. 1/4" NPT male to 6mm OD compression fitting needs drilling through with a 6mm or 1/4" bit so that the 6mm barrel passes through the fitting and bottoms out on the shoulder inside the breech. The optional bolt return spring and guide rod assembly consists of: 2mm OD, 60mm long metal rod Light spring, ie. from retractable ballpoint pen These are not necessary, but can be used to adjust the amount of friction desired. Arrow specifications: 8mm OD, 6mm ID fiberglass arrows should be cut to about 200-250mm length and have the nock removed so that the arrow slips over the barrel. Aluminum inserts, tips, arrow adhesive, as needed, are used to seal the front end of the arrow completely. Models of blunt safety tips are included for shafts with and without inserts and can be glued in place. For 13xx pump guns, replace the front sight plug assembly with the included plug. The forearm liner is recommended: https://www.thingiverse.com/thing:2831346 To use the steel breech or other aftermarket breech for shooting arrows, use these reducing adapter sleeves instead: https://www.thingiverse.com/thing:3265867 Additional assembly and usage tips: Carefully chase holes with drill bits, reamers, and/or end mills to remove print irregularities. Transfer port and barrel sealing is critical. During assembly, install the rubber transfer port gasket on the valve/main tube. Verify the orientation of the transfer port bushing and press it into printed breech. Warped prints likely will not work well. It will be difficult to achieve good seals and the barrel will likely not be parallel with the main tube. Check the fit of all arrows on the barrel and sand the barrel until arrows do not bind and slide smoothly over the length of the exposed barrel.