I browse the EE every day, and the Reloading and Factory Ammo forum hourly. I think the split would be useful, but where does it end?
A better approach would be to enhance the Search capability. The current Search functionality is better than no search capability, but not much better... It is really very crude. Improving it would go a long way to help users find what they are looking for, and therefore reduce the calls for splitting EE (or any other) forums.
I do not know what the underlying DB structure of CGN is, nor do I know what technology the site is using. I do know about large complex DB management and UI design and development, and I am willing to help.