"Glock mag MAC- doesn't Masterpiece Arms make one of those now?"

They do indeed. Amusingly, their MAC barrels are all made on the same exact barrel tooling as their competition winning Precision Rifles. 

The result is these little Ghetto Blasters are shockingly accurate. I've got the MPA 5.7 MAC, its a 1" @ 25yd gun. 

They do, but they're almost $700 each.

Whereas I can likely find what I need for about $300 any of a couple places which basically boils down to a top cocker m11/9 parts kit or parts thereof and then "print a lower" similar to this but with a mag thru grip layout.

What I'm thinking of is a minimum 5.5" bbl with an OD and thread pitch etc compatible with an appropriate linear comp or modded "blast can" with a brake inside and constructed in such a way that I can swap out bottom assemblies relatively painlessly. (Likely an adventure all on it's own)

It's a good starting point and a safe launching pad to work from so that I can start changing things from a "known good" reference point, and frankly I can afford to break parts like this trying stuff. 

There's also metric shit tons of already known good 3d printable parts for something in this particular vein. The Mac upper probably isn't the most ideal starting point being a little large for the hand wrap stance of the cheek pistol when ideally you want an mp9/mp380/b&t usw size body.

There's lots of suboptimal things about the initial design including potentially even the fcg etc since we need this to have a decently usable trigger to work.

But there's enough room inside something like this to work and try things out.

Once I get internals and stuff sorted and everything working the way I want I'll finish one in the modified almara configuration I'm working on just to keep and to play with. 

I have lots of ideas for stuff to change and by the time I'm finished it probably won't be anything resembling the original gun and that's the fun part if you ask me.

I've been gathering up old George kellgren proposals and uziel gal stuff etc because I'm definitely not ashamed to copy something that works.

Yup lol, I'm hoping I can find a masterpiece arms barrel to put in some of my initial monstrosities...

Sorta not looking forward to sourcing or doing my own 22 tcm barrel from a blank if it comes to that but oh man will the results be worth it if I can make something that works half decent!

I also have some interesting ideas on potential operating systems that'll have to wait until further in to try too...

Suffice it to say that I intend to leave less stones unturned by the end of this

Their MP 380 is also definitely an inspiration of mine along with some early kellgren guns.

I consider myself lucky In that respect because there's All kinds of phenomenal ideas that I just need to aggregate and put into a single gun.

Not as exciting or cool as designing something completely from scratch but still a task worth doing.

My new 3d printer and some parts for my other machines arrive between this Friday and next. It'll probably be another 2 weeks to a month after that of assembly, debugging, and workup then the fun can really start.

If it's ok with you I'll just use this topic as my build log etc.

That sounds great to me. 3D printing is a cool and emerging firearms tech, especially for rapid prototyping, so I think having members here printing gats would be well in keeping with the overall discussion of current and emerging small arms. Not to mention, just being cool as hell ;-)

Yeah, I agree.

3d printing is far from a panacea but it has it's uses for this stuff

Update, I have the printer kit here finally. Now to build it.

Oh, and I was turned on to a different control system/scheme to use which should massively improve my prints from day one called Klipp3r which uses a Linux stick pc or something else with an ARM processor to establish more open loop control of the extruders and etc.

I've also found myself a better laser option that I won't outgrow as quickly.

New plan as follows.

Dual Bowden extruder setup, direct drive (possibly dual direct drive setup), and laser capable of limited laser cutting/scoring of 1mm sheet steel etc.

I've also got parts coming for the mill over the next two weeks.

This should get me to the capability level necessary to do what I've set out to do here.

Very cool. Keep us posted. I always wanted to get into 3d printing but lack the CAD skills for that. 

It's way easier than you think, I can almost guarantee that.

I'm not anyone special or anywhere close to a mechanical engineer and I can do it... Hell there's even freecad packages with flowsims now!

Part of why I'm doing this is to encourage others.

Here's a picture of my basement. The 3d printer is in the box by the laundry basket.

As you can see, it really doesn't take much to get started.