The bolt has to weigh a lot more for those other calibers in a direct blowback firearm. In 9mm the bolt weighs about 1.7lbs. For 45acp and 10mm the bolt would need to be 2.3 and 2.8lbs respectively. It can be done but would require a lot of work to change calibers.
There are some frames but I don't think a PDW style chassis has been released yet. I think Chairmanwon was working on a homemade FCU using a SCS flat and bending it with printed bending jigs. If he gets that to work then I see a lot of future development with the RXM.
Check out the Everything Black Powder youtube channel. He makes his own black powder and tries a bunch of different ratios and components. He uses different carbon sources. He also tries ammonium nitrate and sodium nitrate instead of the usual potassium nitrate. Potassium nitrate is the safest and easiest to use. The other two are much more hydrophilic which can ruin the powder, in addition to being much more hazardous to have around. https://www.youtube.com/@Everythingblackpowder
FTN4 is the best printed suppressor out there. There are options for 22lr, 556, 308, 9mm, and 45. They need reinforcement, either an aluminum tube or a carbon fiber sleeve. With suppressors tax dropping next year, someone may come up with a better design eventually. However, the FTN series of suppressors is quite robust and can handle FA rates of fire, especially when it's made of PA6-CF or even better, PPA-CF.
How much of the noise is from port pop and muzzle blast versus the action sounds? The bolt slamming home on my 10/22 is obnoxiously loud and I wear earplugs even while shooting that suppressed. I tend to prefer shooting repeater and single shot firearms suppressed. Don't get me wrong, I'll suppress every firearm I can, but repeaters are a lot quieter than self loaders.
If you want to build a Glock clone, you may be interested in the Invader PDW or the Mando Corser. They're both PDW style Glocks that give you more versatility than a standard Glock lower. If, however, you go with something a bit bigger than a handgun you open up a lot more possibilities. The Decker 380 is a solid gun that can be built for ~$120 and is primarily printed. The PWC-9 or the DB Alloy are also really good builds that use a MAC-11 upper. The CZAR is a great little build. It just takes a VZ61 parts kit, barrel (if it's not in the kit) and an AR trigger.
You could also print out a UBAR3 lower. It can take a standard buffer tube and it's held in place with a u-bolt so it's pretty strong. You can print it with or without an integrated pistol grip. The integrated grip is definitely stronger but not everyone will like it. https://guncadindex.com/detail/UBAR3-X:1
Definitely leaning towards the Q2 since it seems better suited to what I want to do. I'm hoping the heated chamber and higher temps for the hot end will make my prints last longer which may very well make up for the cost difference between the CC and the Q2 in the long run.
I think lowers, glock frames, and other parts that don't get a lot of heat exposure are fine in PLA+. PA6CF is the standard for parts that get a lot of heat exposure like uppers, hand guards, and suppressors. PPA-CF will work even better in a suppressor since it's more heat resistant than PA6CF. I personally want to use PPA-CF for suppressors since they it will actually make sense to print a plastic one next year with the $0 tax stamp. It really depends on what you want to do. Also definitely don't want to leave your PLA+ builds out in the sun in the summer. They can definitely get soft and warp.
The baffles are physically thicker in the FTN series than in a traditional metal suppressor so the entire thing has to be bigger. I did find this https://guncadindex.com/detail/SuppressorPack:2 and it looks like it uses FTN baffle geometry but sealing it up in a pneumatic tube. It has can be built 5-8 inches long depending on your needs. It also appears to be bored for 223 as well. IDK how well it performs. I'll be interested in trying both of them once I don't have to pay the tax to make them.
This is the only broadly usable forum in my opinion. Discord is fragmented and hard to navigate. This is the most like reddit in terms of use, search, and function.
This guy refurbishes older but capable laptops. He doesn't have anything in stock at the moment but they are some of the best value for money for a laptop. They are solid machines and much better than a lot of the cheap crap you can get for the same price new since these are more heavy duty laptops for businesses. https://salemtechsperts.com/collections/laptops-for-sale?page=1
I literally just had a comment nuked on r/fosscadtoo because I put a link to this forum in my comment. I will keep pushing people to join us over here so we don't have to deal with the bs with Reddit.
How is the Box working for you? I've heard mixed reviews about it but there don't seem to be enough of them out there to get a good consensus about how they work.
The bolt has to weigh a lot more for those other calibers in a direct blowback firearm. In 9mm the bolt weighs about 1.7lbs. For 45acp and 10mm the bolt would need to be 2.3 and 2.8lbs respectively. It can be done but would require a lot of work to change calibers.
Edit: Source: https://10mmautocombat.wordpress.com/blowback-bolt-calculations/