I’ve been testing this for hiking and mountain biking. In the main compartment, I used stick on velco sheets to hold in place a repurposed holster and velcro made mag carrier. In the secondary, outside compartment, also with stick on velco sheets, I have the M-Tac organizer (velcro backed), knife, light, phone, and CCW ID (not shown). Due to the small zipper opening of the main compartment, the holster and mag carrier are angled more vertical than diagonal for quick unholstering. Diagonal would be better. I changed out the original clancy plastic zipper pulls for quieter paracord. The bag, velcro and organizer came out to $36, so far it’s holding up and I would not add anymore load. My Camelbak, not shown, holds all the other stuff.
He is experimenting, which is good. Don’t just buy something and start carrying it.
He’s got a nice collection of the basics. S&W Shield 9mm, and extra mag with a Hyve +2 (welcome to California), a Streamlight 1AA flashlight and a Gerber folder. The rest is mostly just window dressing.