So to star off, im not looking to use it. But Ive read a few threads here with comments on aluminum cased ammo and that the keltec manual says not to use it. Ive read my manual twice, front to back and there is no mention of what ammo is a-go vs no-go. Im not looking to buy or use aluminum in my sub2K, but Im also not trying to go down that goofy rabbit hole of misinformation like mini14 guys do with 556. So for those with a manual that does spell out the do's and don'ts of sub2K ammo, is it brass only? Or is steel ok? Im sticking with brass anyways since any steel I see isnt really cheaper enough to warrant steel over brass, but in a pinch for whatever reason, is steel specifically spelled out as no good for these under the direction of Keltec? At this point Im just talking out of curiosity and this deepening infatuation im having with this new sub2K has me eager to talk anything about them, sorry sorry in advance if this is one of those beating a dead horse topics on Sub2K's.