Step 1: Initial Case Interior
Step 2: Remove Interior
The only special note is to ensure you get almost all the hot melt glue out. It is an absolute bear to pull out in some places, but it all has to come out. I left a small bit in my first case and it came back to haunt me when I went to install the retention straps and the final lining.
Step 3: Prep for New Base
The tape will prevent any of the expanding foam from sticking to the aluminum. If it does get on the aluminum it has to be scratched off, marring the finish.
The blue tape will also give a guide as to where to fill the case with expanding foam.
Step 4: Add Expanding Foam
Step 5: Manage the Expansion
Then it's a matter of time for the foam to cure. I left mine for 48 hours but I think the can says it's cured after 24. Read the can.
Step 6: Leveling Out the Foam
As soon as I cut into the tallest part of the foam, I found an area where air pockets had formed.
I simply refilled that are with more foam and allowed it to cure before continuing.
Step 7: Laying Out the Interior
Lay in out and then mark around all your pieces with a marker. The magazines in these photos will be double stacked.
Try to keep in mind where you are going to be adding the retention straps and where they will be anchored to the case.
Step 8: Get Trimming
Once all the outlines are done, put a slight bend on each end of the hacksaw blade, about 2"-2 1/2" from each end.
Use the bend blade to make scoop cuts inside the outlines to remove small pieces at a time.
Step 9: Finish Foam Trimming
The biggest concern is getting the depth right. Taking a bit at a time is best because if you go too deep, it'll require trying to glue your cutouts back in.
For the openings that get down to the outer shell or close to it, I took a bit of the original liner and glued it in. It acts as an additional cushion and prevents any banging sounds while carrying the case.
Step 10: Adding the Retention Straps
I used 1/8" aluminum pop rivets to secure the straps. Right next to the rivets in the hardware store, there were small 1/8" aluminum washers that give a little more grip to the rivets.
I cut the foam back and removed a small plug where the strap is to be installed. Drill a hole through the case shell, and the strap.
Push the rivet through from the outside, slide the strap over the rivet and add a washer.
Run the straps long, you can always cut them back later.
(Make sure the soft side of the velcro is facing your gear. Don't want the rough side scratching up your stuff)
Anchor the rivet down and glue the foam plug you removed back in. (Hot glue, spray adhesive or good ole' Elmer's will do)
Step 11: Pre-fit the Fabric Liner
It helps if the fabric is a little elastic. It helps when getting it into the tight spaces.
I really liked the black faux fur and got a yard of similar material. I think it only ran me about $10.
I cut the yard in half, draped it over the case and started tucking it in as best as I could. I used the rifle and magazines to help hold everything tight as I went. Be mindful of the edges. You want to be at least 2" over the edge, all the way around to make sure you have enough to finish the case.
Once I got it where I wanted it, I cut small holes in the fabric to allow the retention straps through.
Step 12: Glue in the Liner
WEAR RUBBER GLOVES.
Once you start fiddling with the spray adhesive and the fabric, you're gonna be 3 different kinds of sticky.
Step 13: Complete Liner
I did mine one third at a time.
Spray both the underside of the fabric and the foam with spray contact adhesive.
Allow it to get tacky and then work it into place.
YOU'RE ONLY GONNA GET ONE CHANCE TO GET THIS RIGHT.
Once the adhesive touches, it's a pain to remove and re-position.
Once it's in, use your gear to hold it tightly in place. Strap it down tight and be careful not to get the adhesive on your equipment.
After it's all secured, trim the excess fabric so it extends about 1/2" over the edge.
Then, using a small screwdriver or blunt end, tuck the edge of the fabric down between the foam and the shell.
Step 14: Done
The AR-15 case was my second case.
My first one was for my MP5. This one did not have retention straps (big mistake) and two compartments that were supposed to stay closed with magnets embedded in the foam (didn't work and resorted to velcro)
Overall I think they are pretty big successes.
Let me know what you think. Feel free to ask questions or make suggestions for improvements.