WIP - Functional P08 Luger Magwell... for reasons.

Work-in-progress - Making a P08 Luger magazine well assembly.  Why?  To use P08 Luger magazines, duh!  I want a pistol caliber carbine that uses Luger magazines.  But first, a quick look at my design process.

Directory of old, obsolete files

Close enough to work with.

I usually start out with a reference which I download from some online repository such as Grabcad.  The P08 Luger frame I used may be in spec, but it does not translate directly 1:1 when printed.  I used the magazine body to get a rough shape and worked from there.  All those "p08_magwell_*" represents a test and a subsequent improvement.  It's a slow and tedious process.  I have also played around with a 3d-printed mag-catch but was unsatisfied with the results.  I think one is possible, but it would not be compact - it would have to be some bulky AR-Glock mag style mag catch that sticks out of the side, which would be fine for a carbine design but not a compact pistol.

The current iteration utilizes a regular p08 mag catch and spring.  I don't like the flat spring as you'll see below - it's really finicky.  Actually - one of my previous designs uses a clever (if I do say so myself) install process where I got rid of the flat spring and utilized an AR15 disconnector spring.  You just push the mag-catch deep in, rotate it and let go.  But again, that needs more space for a coil-spring housing and it really gets in the way of the trigger finger.  I guess those German engineers knew what they were doing.

p08_magwell_1_02b - spring housing is off.

Testing new spring housing position.

Added angular cut and some efficiency modifications.

Also added spring channel.

Properly contoured to the p08 Luger - and it is print-efficient.

The angle of the magazine is so extreme that it will not fit in a regular AR15 with a simple adapter block.  The lower itself must be re-designed to fit the magazine.  Eventually I will release the p08 magwell as a stand-alone model, my own custom version of U-Bolt AR15 lower, and a Sten magwell.  My ultimate goal is design a semi-auto MP-18 that utilizes both p08 stick magazines and drum magazines.  I don't think the original MP-18s took the stick mags, but mine will.

Still have lots of work to do.

See also: Glock magazine Sten on Reddit, which kind of inspired me.

Cheap 9mm Magwell Adapter (plus mini review)

Just a heads up that Sportsman's Guide is selling 9mm Magwell adapters for cheap. It's made by Promag (I know, bad reputation), but it seems just as good as any other plastic magwell adapter that sell for $100-$150.  The ejector, ramp, and bolt hold-open are steel.  It accepts regular 9mm magazines (including modified UZI mags, but those don't have bolt hold-opens).  When I first got it, case mouths were getting caught on the sharp edges, but some minor hand filing fixed that.  One important thing should be noted about this is that it drops from the top of the lower and requires removal (and re-insertion) of the AR-15's bolt hold-open, so don't expect to be switching between calibers too often.  Actually, I don't even use the bolt hold-open, so I just removed it completely so I can switch out uppers quickly if I want.

TL;DR - if you have a spare lower lying around, this is a great way to get started into 9mm AR15s.