I have done mine by hand with a cheap Lyman crimp removing tool. The crimp on these GGG seem quite severe (rather than being simply staked) with the ejected primers being quite elongated.
I would also suggest a primer pocket correction tool being run in there as well if you can stomach it, just to make sure they sit properly once seated.
The crimp remover only really touches the mouth, the primer pocket tool goes right down to the flash hole.
I have to admit to doing the flash holes as well, but thats only because the primer pocket tool burrs over the flash hole a tad.
I dont know about the swaging tools, Dillon presses etc, I will keep my eye out if reloading 556 is going to become a habit

I have plenty of time and need to keep away from the fridge!!!
I did find that seating a primer after simply de crimping was quite difficult, whereas after doing the pocket it was like priming new brass.
Try a small drop of oil with these tools, it gives a much smoother finish (better primer seal). Its a pain but you really only need to do it once
See you there....I will be the confused looking pleb with a new AR and no idea...apparently
