It now has a front mag which can hold 5 bullets, it's easy to reload and never jams.
The problem with mags on pistols is that if you don't put them in the handle the hole shape of the gun is gone
but this mag is small and is placed where normally a laser would be.
I hope you like it, and if you want to build it here's a link to the original gun just build it and than mod it like in the slideshow. https://www.instructables.com/id/Glock-19/