This is currently on ye olde printer...
Polymaker PA6-CF20, properly Form 1'd, and will have an aluminum tube JB Welded around the outside to reinforce for lesser layer adhesion strength on the Z axis. This is the FTN.4 model available on the strange waters that was designed for PLA+ filament. With PLA+ it is survives well enough with supersonic .308 rounds. With PA6-CF20, it should last as long as anything commercially available for my intended use of my .300 BLK.
Also, I decided to learn how to do CAD, and whipped this up as a beginner project on Tinkercad over the course of a couple days. Designed for .22lr; i will be submitting Form 1's for this on January 1st when the making tax goes to $0.
The first is a cutaway showing the internal baffle system. Second and third are the same with one having a rounded front edge and the other squared off. Fourth is relieved to allow for a 38mm aluminum tube to fit around the outside for reinforcement, and the last just has a relief for a short ring section of the aforementioned tube to fit around it for Form 1 engraving purposes. I'll probably have to refine these a bit to get the clearances for the fit between the aluminum tube and the core just right, and my baffle system is it a bit experimental, but it's all part of the journey.