Newbie to 303 surplus spam cans

So I decide to get myself into a new caliber during one of the worst ammo shortages ever.

asbestos is generally used where you would want insulation, 

asbestos isn't some magically evil material that attacks you.  you have to break it, cut it or smash t to release fibers into the air.   the stuff was everywhere in the good old days.

You are correct about asbestos. If in doubt, wet it with water and put it in a zip lock bag. It becomes a health hazard when "friable", or the small particles dry out and become airborne. I saw miles of the stuff removed from piping in fertilizer plants that were built in the '60's. They would hoard the area off with 2x4's and poly, wear approved tyvek suits and dust masks and wet and bag the old insulation.

The bandoliers look similar to the lightweight "throw away" bandoliers used in WW2. 

What does the case head say? Like RG44 ?