For rifle calibers, I'd agree completely. But for a 9mm PCC, the bar is a lot lower. I wouldn't unconditionally recommend all the OKB 69 designs, but I've heard the Pr. 27 and with 9mm subs I thought it sounded good. Is the FTN better? Absolutely. That's why it was at the top of my list. But for some people, the ease of a non-reinforced design might be worth the trade-offs. If tax stamps were still $200, it would be a different story.
The FTN.5 PCC Flow has excellent sound reduction and reduced backpressure vs. the standard version. Simple blowback 9mm PCCs are noticeably more pleasant to shoot with a low-backpressure can.
If you want a quiet non-reinforced (fully printed) design, the Project 27 Mashina from OKB 69 is quite good, but it's a bit of a beast from a size/weight perspective (1 lb and 10 inches long). It's also a traditional non-flow design so you'll get more gas to the face, a more felt recoil, and the action will get really dirty. If you go that route, use the 3/4x16 threaded blast chamber with a metal thread adapter since the 1/2x28 printed threads just don't hold up -- especially on a can that massive.
Be aware that even with the best commercial suppressor the gun will never be super quiet. Simple blowback actions "leak" a lot of sound when the bolt opens. Delayed blowback designs like the MP5 and Kuna make better suppressor hosts.
There is an M1 Garand in the Black Lotus Coalition Reference Model library: https://odysee.com/@FirearmReferenceModels:6/M1-Garand-Reference-Model:1
However, you'll need to use a CAD program to extract just the buttplate part as an STL. If that's a big ask, let me know and I'll try to hook you up.
Are you running a milspec trigger or aftermarket? Any other trigger shenanigans like a super safety? I'm not sure I understand "lining up the trigger springs and disconnect spring". A photo of how the FCG is installed in your lower might be helpful.
If only they'd had this legislation sooner perhaps a tragedy could have been avoided. Wait, how many of the Bondi Beach firearms were 3D printed? Oh, that's right -- NONE!
/s
Does that "every way" include respecting your privacy and not locking your data into a proprietary undocumented format?
I will grant that FreeCAD is not as polished as F360 (though it has improved significantly in the last couple years). It also forces you to be more disciplined about design and especially sketch constraints (which I consider a good thing). But I have not found a significant productivity difference between FreeCAD and F360 (once I spent the time to understand FreeCAD's way of doing things).
Don't get me wrong, I'm loving the $0 stamps, but it has kind of ruined the cachet of "Two Stamp Tuesday". lol
Build details: DB9-22 (Phoenix Design Works SS receiver) in Siraya PPA-CF, Carbon Folder stock, MM Soaked Noodle grip, mag and grips in PCTG. FTN.5 Rimfire Flowthrough in Siraya PPA-CF (annealed). I didn't appreciate how big the FTN.5 was until I printed it, but I really like the looks on this build (makes it look much more "serious" than just a 22LR plinker).
With Unseen Killer's help, I was able to determine that my Franken 9 problems were entirely due to using printed Sten mags. There was a different problem that affects only milsurp mags, but that's fixed in UK's latest drop. If you're using milsurp mags, print the latest frame and you should be good to go.
The problem with printed mags is that the dimensions deviate significantly from production magazine drawings. Every design I checked was wider at the feed lips and flared more steeply than specs call for. Most are also about 1mm shorter font-to-back. As a result, they won't seat deep enough to reach the mag catch or feed correctly (or at all). To be clear, there's nothing the Franken 9 can do to fix this -- the incompatibility is with the Glock slide itself.
I didn't want to print new mags just for this build, but curiosity got the best of me. I remixed a "spec-ish" version of the DMB Sten v1.1 and squirted a test print in PLA Pro. With that the Franken 9 is able to feed 100% reliably in dummy round function testing. I haven't been able to range test yet, but if that goes well, I'll post my spec-ish Sten mag remix for anyone that wants a non-milsurp option.
After a week on the struggle bus, I think I'm going to throw in the towel on the Franken 9. I love the concept and there are some really clever design elements. The problem is that I just can't see how to get standard printed Sten mags to work reliably. With a modified mag catch, I was able to get my build to accept a printed DMB Sten mag and feed dummy rounds. But it's hard to get the mag to lock in (because it has to be held right up against the bottom of the slide) and it's very easy to induce a failure just by bumping the mag.
The fundamental problem seems to be that printed Sten mags present the rounds about 0.8mm lower than Glock mags. That means the feed protrusion on the slide just barely catches the rim of cartridge in the magazine. It can work, but there's no margin. Mag fit relative to the slide has to be absolutely perfect. It might work better with surplus magazines (I don't have any to test). It also wouldn't be too hard to remix the printed mags to be a little more compatible, but I'm just not eager to print off a set of "one build only" magazines.
Though I'd really dislike the aesthetics, I think a version of this using Glock mags would be a definite improvement in function/reliability.
My revised mag catch is up on Odysee if anyone wants to give it a try: https://odysee.com/@KopsisEngineering:a/Franken9-Revised-Magazine-Catch:e
All practical 9mm handgun designs are "parts kit" builds that rely on a conventionally manufactured (machined steel) slide and barrel. If you can't find links to those yourself, you shouldn't be building your own firearms.
For a fully DIY 9mm firearm, you're generally going to be limited to something along the lines of the FGC9. And even those need a steel barrel so if you can't buy one, you'll need to learn how to machine one (either conventionally, or with electrochemical processes).