I have 3x 50rd and 3x 30rd for sale. The 30rd have been repackaged in boxes that say 50rd on them. Otherwise I believe these to be new. I bought a gun that came with 13 magazines and decided to only keep 7 of them.

Conversion kits are available for 30rd to 50rd magazines or you can modify the end plate with a dremel for free. But I didn't want to sell a modified item and be liable for that, so they're sold as they come factory.

Will also trade for HK branded MP5/SP5 magazines.