Been working on this pretty frequently, testing and tweaking since I finally got my F1 approved by the ATFE.

Someone asked for a 22lr/556 variant. This one is bored to 6.5mm to accomodate .224 diameter boolits.

Current version v20. Abandoned the DNA-inspired helix aspect of some of the previous designs and went for smaller and more channels running the length of it, which feed the blast chamber gases to the front of the can and into the brake. The helix worked, but its unsupported nature led to failure sooner than I wanted, and some printing technologies couldn't print it at all without supports. Tried to balance the internal support structure for the cones while trying to minimize internal volume loss.

The idea is that the bled-off gases that run through the narrow channels feed up to the top and help feed the brake. The alignment of the core and the cap does not matter with this design.

Works in 1.355" ID tubes, this one is optimized for a 6.8" tube I had lying around. Center bore is 6.5mm. It should print pretty well with every technology I've tested, but I am mostly making it out of FDM PPS-CF10 printed at 340 °C. Other versions exist, but went unpublished, as I felt time was better spent improving the design internally than flooding the market with ever-increasingly improved iterations. I probably won't update this again for a while, I have other projects I'm starting to work on. Unless I get actual feedback from users on ideas to improve on it based on usage.

Most rounds through this design have been with an 8" barrel 9mm PCC (other 11mm bore variant).

Endcap/brake threaded for 1.4375X20. The endcap is designed to be tightened with a wrench.

LBRY Tags: ftn4; oil catch can; 3d2a; silencer; fosscad