In the first instance, the case cannot store securely multiple rifles. Collectively, individual cases and their respective padding take up too much room. The idea is to provide a weatherproof, secure means of transporting an AR collection in the event of a forced evacuation. We had four last year.
The fifty-five gallon drum approach provides no greater ability to secure weapons for transport and, put simply, doesn't fit inside an SUV. In the instance of the case for which this thread was created, the steel drum approach would require considerable customization. They're also problematic to transport via commercial air carrier.
Hence, the necessity for using a mobile armory case which has been tested and has passed federal regulations for transport. What I'm looking for is a manufacturer who not only makes such a product (I've already named two who do), but also has a retailer interested in selling them.