H&K MP5 9MM MAGAZINES Reviews & Ratings
Don't worry, they will make you happy
I've bought several for my PTR. ETS just works. Yes you have to lock the bolt back but that is standard for an MP5. I even use the 10rd occasionaly.
If you like the look I'd try one.
I used these Zenith Z-5RS with Fiocchi 115 grain 9mm. Ran 90 rounds through both magazines without any issues. Upsides are they are lighter than standard MP5 magazines and functioned 100% for me so far. They also let you easily see about how much ammo you have left obviously. Downsides I noticed are they fit very tight in the mag well. I had to work them in and out for a little while before they became easy to insert. Another downside is they are just slightly longer than a standard metal MP5 magazine, not a huge issue but something to note. I you like the look of these, I'd buy one and see how they function in your gun. I had no issues but the other review seems to have had a lot of trouble. For my Zenith though they were 100%, and just a little tight in the magazine well.

