I think you might be looking at an old copy of the commerce document.. the most current (Feb 2023) is located here:
https://www.bis.doc.gov/index.php/d...ties-equipment-and-miscellaneous-items-1/file
you also have to read pretty much for a page or so in advance and after the mention of whatever it is you are looking for to make sure you have the full context of what they are saying... the commerce document in particular is horrible about stating things like "exceptions are"... a full page prior.. or saying "this was regulated by ITAR previously" completely out of context for what they are saying now...
what you are seeing in the version you are looking at are components to what commerce calls "inherently military munitions".. which are defense articles controlled under ITAR (uranium depleted shells, howitzer rounds, etc..etc..).. so they are saying if youre dealing with a part or component of an ITAR controlled item.. the component if not itself ITAR is controlled by EAR..
They make this slightly more clear in the newest version.. you'll find a similar "note" in the new version.. its Note 1 to 0A505.x in the new version.. where they make the same statement (primers, metallic cartridge cases, etc..).. but 0A505.X clearly states in the new version that what they are talking about is parts or components specifically designed for a commodity that is controlled by ITAR (military munitions)..
Hunting, range plinking, etc type ammo isnt ITAR.. therefore the components are neither ITAR or EAR..
To your point.. the US Regs are inherently difficult to navigate.. they are poorly written.. often contradict.. different agencies are in conflict.. etc..
To make it worse.. we have been going through export reform at the federal level for more than a decade at this point.. every year they make fairly large/sweeping changes.. its become something like trying to keep up with US federal tax code.. what was legal last year is now illegal.. and what was illegal last year is now legal.. what was regulated by ITAR last year is now regulated by Commerce.. what was regulated by Commerce last year is no longer regulated.. and what was not regulated by anyone last year, everyone now wants to regulate..
Even though they just updated the commerce regs less than 60 days ago.. I feel pretty certain they will update them again at least once more before the year is out lol..