Drop free pre-ban 30 rd extended mag

Ok so as you can tell I live in NY. We have a 10 rd limit for mags unless you use pre-ban mags. Then you can add extensions to your content.

So I got a pair of U-notch non-full metal lined mags. They do NOT drop free. Also I had issues with the follower snagging where the mag meets the extension.

So I found a square notch pre-ban mag on a forum for sale. The square notch mags are full metal lined and supposedly drop free.

Well I can confirm that they do drop free. However the follower still snags inside the extension. Another problem, that did not exist with other mags, is that the square notch at the top of the mag is too narrow for the KRISS bolt. The bolt can't close all the way.

So I filed the metal square notch a bit to widen it and allow clearance for the bolt. I then took a sharp knife and beveled the bottom of the mag so that the follower doesn't snag.

So now the mag works. I loaded it up with 30 rds and thumbed out a round at a time. Now I need to clean my KRISS and shoot it to test if the mag is reliable.

I took a picture looking down the mag so you can see how the follower is snagging.

A little update on the Preban Square Notch mag. It works sometimes. The bolt closes about half way. If I load a round first and insert the mag on a closed bolt, then it works.

I think the feed lips are a bit too tall.

Here is a video i shot today.

Great videos