[CJ of FL]

I've read some of the 10mm HK converstions use STI mags, but I've checked http://www.stiguns.com/ and they don't have any 10mm mags. Did they used to make them? Or am I missing something?

 

[straightgrain]

The magazines used in the converted HK weapons started life as an STI mag and then modified by the builder. They are not a production item from STI or HK.

 

[eric10mm]

www.midwayusa.com
www.shootersconnection.com

Both sell STI magazines. The ".40SW" mags also work with 10mm.

 

[Kost]

Im sure Big Chris would sell you more than one 10mm mag when you buy one of his 10mm conversions. Its probably best to buy them from him, instead of attempting to make them yourself. Big Chris is a pretty good gun smith - he knows what hes doing.