First time I've heard of anyone having this issue, or anything similar. My 1st guess would be support material or something like that in the trigger housing.

I've done them different ways. Threading works fine, but eventually will wear out the plastic threaded part.

I usually run them until they get loose, then JB weld them in.

Depth isn't very critical. I usually run mine a little deep. I've tried quite a few different iterations of the printed portion of the firing pin, and not too much different performance from making changes.

I haven't broke/wore out any of the JB welded firing pins, one has over 1000 rounds easily.

It's something that has been worked on, but I have kinda lost interest in it. No one wants to help beta test it. I've gotten it to cycle a decker. Someone apparently got a modified fgc9 to cycle 9mm deep, but I haven't seen it. Another guy in BLC was working on some other modified 9mm cartridge in the decker platform as well

As for energy, it was closer to 22lr. And 32 auto has about the same energy as 380, so yeah, it's not that powerful.

So far all of my ammo projects are for manual actions. It just works better, and these kinds of guns are still really neat.

People get real wild with the filament stuff for sure. I have one of these same builds in matte PLA, and PLA-F. My Modelo has silk PLA and normal PLA parts on it that are all original 2000 rounds later.

I don't recommend people use these weird materials, but I like to put it out there for everyone just as another data point.

My barrel nut for my 21.5" m4gery is this same PETG-GF and it's been working great. I broke my PLA+ barrel nut.

I think hoffman recommended PET-GF, not PETG-GF.

But as far as differences, it prints just like PETG. I did have to run the nozzle at like 260C. It does require drying. It's abrasive, I ate 1mm off the face of a brass nozzle in about 300 grams of material. Steel nozzle has been gone for the remainder of the roll. It needs to be dried, but overnight @ 70C was plenty to get it dry and was good for a couple days afterwards. Nothing like drying nylon.

I have done a couple other parts, such as hd22 barrel nuts, Glock mags, 10/22 mags, etc. I did some destructive testing with Glock mags and they held up really well.

I don't do much with parts kits builds, and these little suckers are easy and cheap enough for me to build just as a test. I know what to expect out of them with other materials such as abs, PLA, and pla+. The breech, sear, and hammer are typical failure points for this particular build and get different types of stress.

It does have rifling, and it doesn't keyhole.

And you are correct about accuracy in relation with the sight placement. As is, these will get you a 3" group at 20 feet on a good day, which is more than reasonable. I have an 8" pistol that I've hit steel @100 meters with a scope a few times, and the scope is mounted on the barrel.

Don't have any more info on that. But chronigraphing your rounds should be enough to get you a starting point with a little bit of math.

Just have too many projects going on, and I really like my Modelo. Nothing else.

What you are asking for with the 9mm chamber is already finished and released. It's called "the 9mm deep". It's available on BLC odyssey. There is someone who got it to cycle in a modified FGC9, but I would totally wait for the 9mm decker to come out, as it works better with printed ammo than any of the FGC variants. The biggest change to be made is bolt weight.

We do the ammo development at BLC in the BLC element space. We are always happy to have more testers, and the process to become a tester is pretty painless.

I have pushed the 380 printed ammo project aside for the time being, lately I have been working on 38 special printed ammo and more 43R loads, some of which I will be releasing later today.

There are a ton of people interested in the printed ammo, but hardly anyone willing to help with testing.