Kind of, it was sort of stated, and I think it was implied by the shield from The Illiad that what happens was something that you lost with the invention of the printing press, at least part of the issue is. Before the printing press you had oral legend and a bunch of guys copying things from an older copy to a newer copy. With oral legend, some bits are forgotten, so the bard/what have you changes the legend just a bit, or some things are remembered wrong, but the result is the same, and all of them are accepted as the "true" story, because people expect them to remember everything perfectly. In the case of the literature, the monks made mistakes, yes it happens less, but there were still mistakes made. To tie this back to the shield, the story got so crazy and out of the bounds of what the shield actually was, it ceased to be an actual shield at all.
In the case of the weapons, well, they needed a unique weapon to identify with, as well as the bits that are beyond what we could do, as Nairit said. The only character in the Nasuverse who gets to that point with a gun is probably the Gun God, who kills a Type. Types being the ultimate being of a planet, and some of them described as basically throwing around magical nukes like they were nothing. The death of one (killed by Ado Edem with Slash Emperor, not the Gun God) burned an entire continent. The problem with the Gun God is that his gun, the Black Barrel, was designed specifically to kill things like that. So it still doesn't make that jump into being beyond what should be possible. In any case, Ado Edem has a higher kill count, so even if all the other conditions were fulfilled for the beings that left into space, Ado Edem would be the one they told stories about, Gun God would just be a side character in his legend.