No the GSG magazines will not work with the HK. The HK mags will be 25 rounds not the 22 rounds of the GSG's. The lower on the HK will not be plastic like the GSG but all steel uppers and lowers.

The official HK web page is http://www.hk22rimfire.com/ if you want to see more. George Horn up at The Gun Room will be getting some in.

I like the gun but I too will never give HK any more money.