I mean the size of the port on the bottom. The longest case that will drop out is a 6Dasher probably. It sure would be nice if you could make it longer to drop a 6.5x47 size case. I was looking to see if anyone had tied this.
well..... there are a lot of the drop ports that have been made into HBR's. And the most prevalent cartridge in HBR is 30x47....... so I would guess it works.