I imagine it’s going to resemble a 5.56 chamber in short order anyway…
Or rather the throat will. The chamber will remain the same and identical to the 5.56 already.
The longer, larger diameter throat and shallower lead into the rifling reduces pressure, that is then replaced by loading the case to “5.56 NATO”.
So, if the bulk of what one will be shooting is NATO type ammunition, I would get a 5.56 throat. A shorter steeper throat may increase pressures, in an otherwise already intense loading.
This extra pressure will cause the rifle to cycle more quickly too, perhaps causing unnecessary wear.
The Wylde chamber was to bridge from the NATO Safe 5.56 to the accurate commercial .223. Yes, no one wants an inaccurate rifle, but that’s not part of the argument with a machine gun. That also doesn’t mean there aren’t very accurate 5.56 chambered barrels.
If I was handloading to feed a hungry flame thrower as cheaply as I could. And also seeing some pretty scary bulk ammunition results that I wouldn’t want through my registered lower, I would purchase what ever chambering was available for the barrel I wanted and load for it. Knowing it will soon have a much worn throat, lead, and gas port, and still be having more fun than human being should be allowed to have!
Since I cannot afford the fun of a full auto, even with handloading, and don’t have one, and envy you greatly for it, you hardworking lucky bum, I can’t speak from true experience.
In that light, could I ask for maybe a build thread or a range report?
The closest I have is a binary AR I use with a dedicated rimfire upper. And while fun, a lot
, it’s not the same. Hopefully when I retire there will still be some M-11s around for me.(Sigh.)