Prototype of +1 Magazine Extension

[Alfonse]

Here is a printed plastic prototype of a +1 round magazine extension. It allows me to get my pinky on a PM9 sized Kahr and makes the pistol 7+1.

I would love to hear thoughts on it.


Here is another shot of it:

[Dreams_of_Steel]

Looks great Alfonse! Will those base plates be interchangeable with the stock ones?

[Alfonse]

Looks great Alfonse! Will those base plates be interchangeable with the stock ones?

The real ones will look much better, but printed plastic parts are fantastic for testing and checking fits on things. You just take off the stock base plate and retainer. Compress the spring. Slide the new base plate over the bottom of the mag and insert the retaining screw with a 5/64" allen wrench. Removal is simple too. Remove the retaining screw and slide it off being careful to keep the spring from flying out and hitting something you don't want it to hit.

It fits 6 or more round 9mm magazines.

That photo is one of my test PM9s and has a grip sleeve on it. I should have used something without the grip sleeve so the contour at the interface to the pistol was more obvious. Oh well.

I have had no problems with any of my mags with feeding. For most of the mags, extra power springs are available from Wolff, but I have seen no need in my testing.

[JohnR]

Looks good. I'd rather see something that extends the whole grip cross-section like XD extended mags do.

[b4uqzme]

Looks good. I'd rather see something that extends the whole grip cross-section like XD extended mags do.

+1 something that really finishes off the bottom of the grip would be great. But I would only want that for my primary mag. It would be too bulky for backups IMHO.

[Alfonse]

I tried that. They get pretty bulky in 9mm. On the other hand, it works pretty well on the .380s. I do have some prototype sleeves, like the XDs uses, that fill it all in on a Kahr extended mag (7 round mag in 6 CM, PM, or MK), but rigged that way it is quite a bit larger.

The other thing that happens is you would have to have a gap for a slot to get it apart since the spring drops down in the extension. It won't come apart otherwise. The gap isn't great.

[Ronni3_J]

This would be great for the 380 modles

[Alfonse]

This would be great for the 380 modles

Because of the relative sizes of everything, the 380s will probably not curve out and just match the contour of the grip on the front. They are a bit behind the 9mm though schedule wise.

[Scarywoody]

If you told me even 5 years ago that you could design and print out a prototype I wouldn't have believed it. Amazing!

[Alfonse]

In the late 90s it cost about 800 bucks and took weeks to get stereo lithography prototypes. Now, I just send a file off over the internet and the part shows up in a few days. Most parts I would get change back from a fifty.