It has been a while since I have contributed anything so I figured I would share a set up I use with pretty good success.
Working closely with some area LE Agencies I'm generally asked to come out to shoots or qualifications for Armorer work on Patrol Rifles and Handguns. Here is a kit I have made up after a couple years of working at it that has worked really well for me. Keep in mind this is basic tools to fix issues on the fly so they can continue then come in if its a major issue.
When I initially started doing this I knew realistically I would not be able to fix everything but wanted to be able to handle a majority of issues commonly found.
First I needed a decent kit bag to start with that would hold all my necessities. I just happen to have the perfect bag laying around it's made by Wilderness tactical and I got it at a show a few years back and never used it because it was always to small but it works perfectly for this. It Measures 13L x 8W X 7T it also has some outer pockets. I'm thinking you could also find something similar at any surplus store.
Main bag loaded full
Here is one of the side pockets, I keep both wrenches and a vise block in it.
The mains compartment houses the bulk of the tools and a separate bag of small tools.
Here is the separate bag its a medium molle gear pouch I had laying around.
Here is the contents, I found for keeping all my punches together a molle pistol mag pouch works great. I keep driver bits on the strips and plenty of allen and torx tools Not pictured is a small bottle of synthetic motor oil, small bottle of CLP, and small tube of greese.
Here is a list of tools I keep and frequently use
Small Desk top vise, its not the best but it works well in a bind especially if you have a extra set of hands to stabilize the rifle.
Vise Block, Receiver Block, Front sight block, Neoprene mat
Mako Wrench, DPMS HD Armorers Wrench
Ball peen hammer, rubber mallet, punches of all varieties doubles of all the smaller ones in case they bend or break.
Bit driver, with tons of bits. I have since replaced the one in the picture as it was on its last leg. Sets of metric and standard Allen Keys and Torx Head. I also keep a T Handle torque wrench
In the poly baggie is H2 buffer and Recoil Spring, JP Spring Kit, 2 Trigger Pins, Complete FCG, Complete Bolt, Cam Pin, Firing Pin, Spare Gas Rings, 2 FP Retaining Pins, Detent Springs and Sling plate adapter.
I keep 3 of those in the Kit and 2 Spare Car and Mid Gas Tubes.
All in all it has come in handy several times while at the range, you can obviously tweak it to your specs and desires this is just what worked really well for me in the past. Figured it might give some ideas to those who use and shoot AR's a lot and go to shoots and wanted to be prepared to repair!