Before this gets too deep, let's go to the origin. Eugene Stoner.
Well shiit, he developed the first AR-10 (Fairchild/Armalite, founded 1954), and that led to the AR-15.
Here's history on that, to avoid confusion:
https://www.armalite.com/Armalite/About-Us
Later on, Colt developed the future AR-15s (M16s) for military use - and Eugene Stoner worked for them, when that happened. Period, End of story. Colt didn't do it. The man they hired did...
Okay, so now into the future - the Knight's SR-25 .308 Win rifle. C Reed Knight didn't develop that rifle - he hired Eugene Stoner, and Eugene Stoner came up with the SR-25 rifle. Yeah, real story. The SR-25 turned into the KAC M-110. There's no wonder why, or how that happened.
There's a very critical Common Demoninator in all this - and it's Eugene Stoner...
And here we are...