I'm interested in the card stock idea.
Forget the sheet metal ideal, Use file folders. The bage kind.
Remove the action from the stock. You'll see the indentations on the stock where the action fit.
One on each side of the mag well, and the horse shoe shape to the rear. Cut the folder material to fit. Use two layers.
Now, where the trigger group snapes in, you'll find two places (one on each side), Cut pieces to fit this spot. Use two layers.
When you put the trigger guard back in you should really have to force it to snap it in.
Now you have it bedded, Leave it alone. It should last quite a while.
Now there should be a gap where the gas system fits the stock. You'll have to squeese the stock toward the barrel to see this. Take a q-tip or something and force grease into that space. It should now be free floated except for the grease.
You don't need to take the action out of the stock to clean and lube it. Look where the op guide rides on the chamber, grease it. Grease the rails where the bolt slides back and forth. Grease the op rod where the bolt rides. Force as much grease as you can in the roller part of the bolt.
Don't over clean the gun. More guns are ruined by over cleaning then shooting dirty.
Only clean the piston when it sluggish slidding back and forth. Use the shot shell rod guide and stainless one piece rod sparingly in cleaning the barrel.