Simple part files for single, dual, and triple magazine securing trestles. Glue to the underside of your deck, with the smallest towards the magazine loading port and the tallest towards the gun interrupter. Makes sure your gun magazines roll downhill towards the tee. Slip a ziptie through the hole in the mount and ziptie the magazines to the mount. Presto.
I've used similar parts for almost all of my builds but never thought to share them, so here ya go.