There was a claim some time ago by the late Jim Schatz that HK drilled EVERY 416 gas port in the grooves of the rifling...
Here's a lovely example that is in line with that claim...
And here's a nice pic of the beautiful chrome lining (not that it makes any difference, it's just quality work)
However, here's an older 416 that I was using pretty regularly (AF or AG date code). Whoops...looks like they don't always hit the groove.
And here's a stellar example of a different "high-end", highly praised, never-in-stock mfg where there were claims they also tried follow HK's model... Not only did they fail to hit the groove but they left some damn big burrs to get worn down there.
I like high-end stuff as much as the next guy, but sometimes you ain't getting what they tell you you're buying.