[SkaerE]

works for the springfield XD's.   i think it works with glocks.  why not for P99's?  seems you can generally fit about 15 9mm into a 40 mag. sometimes you have to "tweek" the top of the mag a bit, but heck, even if you dont trust em for anything but range work...tha'd make a cheap high-cap.

anyone try it?

 

[Bruz]

Heard about that also but never tried it...just bought hicaps instead.

 

[Catbird]

I am VERY familiar with the Springfield Armory XD magazine procedure.

The Walther P99 .40 Auto magazine body will accomodate 14 rounds of 9mm ammunition.  Without fairly substantial feedlip adjustment and a 9mm magazine follower, it is my opinion that the same procedure enjoyed by XD owners is not feasible with the P99s; I have "toyed" with the possibility.

Please remember that modifying the .40 Auto P99 magazine to function properly in a 9mm P99 would cause this magazine to (more than likely) become useless in the gun for which it was originally intended; THIS IS ILLEGAL.

In contrast, the slight adjustment required with the .40 Auto XD magazines to function perfectly in both caliber XDs, apparently, is not illegal. Please be advised that I am not qualified to render legal advice.