Have read that some exist, but hell if I can find any leads. Any help appreciated, and TIA.

I cannot answer your question, but maybe Dennis Chang can.

If you "Goggle" in the "search words": Rec.Guns FAQ
you will be able to click into the site, 'Welcome to Rec.Guns on the Web'.

From there click the box: 'READ THE rec.guns FAQ'

There, on the OUTLINE click: 'III Firearm Information By Type'

On that page click: 'C Semi-Automatic Pistols'

Scroll down to s. Sphinx and click: 'AT-380 M'

There you will find an article and comments by Mr. Chang regarding your pistol, and he also states that, "a 15 round magazine is available". (A lot of interesting information on this topic and others on this site.)

Mr. Chang will welcome your inquiry as he closes with:
"Send comments / questions to Dennis Chang. (Be a man or woman-- if you are going to send rotten letters to people, take credit for your actions.)

This contact may be of some help to you in locating the magazine. The article also informs:
"Sphinx is distributed in the U S by Sile Distributors (address unknown). Sile handles the warranty. Their contact number is now (the one in the phone list is no longer current)

-- New York 1 800-221-9428
-- Connecticut 1 800-243-3404

Both locations have a gunsmith that is specifically trained in repair of Sphinx arms and have genuine parts."

(Hopefully, including hi-cap mags for your fine Swiss pistol.)

Dennis Chang- trylaen@cco.caltech.edu

Good lux,
-weed