5.56mm
With one company making such guns known for rudeness and another for shoddy quality, it was nice to hang out with friendly people who make good 5.56mm, 7.62mm and 9mm roller-locked guns.
7.62mm
By accident of lighting and timing, we can even see a blurred bullet coming out of the muzzle.
9mm
It was worth braving the cold for seven hours to run a lot of ball and tracer through these guns and a stray MP40 as well.
PS: I also shoot a PTR91 which has been perfectly serviceable and quite accurate for me. There rifles were a good deal smoother, which is as expected from custom-built rifles.