read ATRS's previous posts about that as I asked that question directly. I still do not have a clear answer that parts enabling me to build another caliber upper would be available for sale from ATRS
His response inferred that ATRS may be sued if I built the calibers I want on his rifle after I have purchased it from them, so I do not really know what to think.
My understanding is that once a particular cartridge gets a SAAMI specification, there's no real "rights" per se about that cartridge. It becomes fair game and anyone can ream a chamber in their guns. This is why for so long, you could only get the 6.5 Grendel or currently only the .50 Beowulf from Alexander Arms. AA recently released the Grendel specs to SAAMI, and it has a few people south of the border pretty happy. So from what I've learned (I actually spent tonight's shift at the bar looking it up on my smartphone) that once the creator releases the rights of a cartridge to SAAMI, it's fair game to everyone, and no longer proprietary. If the .450 Bushmaster hasn't had the rights released, then you're SOL. Ditto with the .30 Remington AR. As far as I know, 6.8 is SAAMI listed, so it's fair game, hence why you see enough guns chambered in it now.
I agree that we should be offered stripped uppers, or even DIY upper parts kits to build uppers suitable for our wants/needs as individual shooters; I'll reference the plethora of options for the AR15... if the barrels are compatible, it's easy to source whatever you want, ditto with the bolts. If the barrel extension is different which I'm led to believe it is, then sell us a kit with the stripped upper, bolt carrier and barrel extension. Let us figure out/source the rest on our own.
For now they have said only 223 and I think it's fine to say I would like 300 black as an option in the future and leave it at that but there are some people here that have been trying to argue and posted multiple times about the same calibre in multiple threads.
Rick has already flat out said no .300BLK, because he's concerned about the risk of a KB and the potential liability due to subsonic ammo from an 18.5" or longer barrel. I can agree with his reasoning for subsonic ammo, but supersonic should be fine. There are other alternatives too, like 6.8. The bolt face for 6.8 is only 43 thousands bigger in diameter, still smaller than a 7.62x39 bolt face. I know he's mentioned his concerns about bolt failures when running a larger face, but even .223 bolts have failed. I see the bolt that Stoner designed as being consumable, given the teeny little lugs. Three larger, meatier lugs would be stronger, or increasing the web for the locking lugs (similar to what KAC did with their SR15 Enhanced bolts) and would only need the corresponding change to the barrel extension. There is also the option of using a different material, but that can drive the costs of machining and tooling up even more.
Dont forget you are the consumer to, we have a thread where we can give them an idea
Of what we want to spend our money on and you want another generic 223. Ar varient?
Variety is a good thing
Exactly what I've been saying all along. I don't want another .223. I DO want a versatile, multi-caliber gun that I can take from shooting .223 at gophers or 3-gun to a whitetail hunt by swapping uppers. Hell, I'd gladly sell the rest of my guns, even my beloved AR15 to own that gun. I had high hopes for the SIG MCX as being that gun, until the FRT came out as restricted as an AR variant.