You can use CMC 10 rd .45 mags if you "tweek" them a bit. The Metal Form 10 rd. .45 mags require no tweeking to function. I do load my .40 out to 1.200", but my gun will feed short rounds also. The only downside to the Metal Form mags is the little tab that prevents over insertion. It will chew up your frame. You can do one of two things to fix this. Weld a small piece of key stock in it's place or buy the 10 rd. Ed Brown mags. These are SS Metal Forms with a base pad and a welded on stop. Downside is cost. "Gunsmith" price at Brownells is $30. If you choose to stay with 9 rd. mags. I can recommend the 9 rd. Metal Form 10 mm mags.
[This message has been edited by Joe D (edited 10-10-2001).]
I have a Caspian single stack in .40. The Metalform 9rd 10mm mags work just great. I have also found that Wilson 8rd .45 mags work well also. The Wilson's will hold 9 .40's.
"And by the way, Mr. Speaker, The Second Amendment is not for killing ducks and leaving Huey and Dewey and Louie without an aunt and uncle. It is for hunting politicians like (in) Grozney and in 1776, when they take your independence away".
Robert K. Dornen, U.S. Congressman. 1995
Para Ordnance makes 10 round mags that fit flush in the pistol
I know thats not the info you wanted but it is a different perspective. My P-16 is a little rough around the edges compared to my Custom Classic. But with the new enhanced features Para put on the standard models it will get the job done, which in my case is IDPA and a little 3 gun.
I talked with CMC yesterday about a 10 rd 10mm mag. They said they have had several calls from customers looking for them. Perhaps if enough of us called them (800-328-2447) they might start producing them. I doubt that CMC makes their mags so maybe a call to Metalform would help also.