Board Thread:Warhammer 40k General Discussion/@comment-10051320-20130526124353/@comment-5846164-20130526143235

it is now rarely ever deployed by Space Marine Chapters, if their Armouries possess any at all.

its from the wiki, that is the only thing saying anything about who and who not who have it. but there is no reason noone else should be able to use it, maybe the ultra name is a ultramar  trademark, and may only be used by their representatives. good question tho.