I took my 7.62 Norinco AKM to the AAC Silencer Shoot last weekend.
The weather was rainy and muddy, perfect AK weather.

I fired several mags of plain jane Wolf ammo through
my SEI/Fisher M14DC 0.30 Caliber Sound Suppressor.
Results:
Very accurate (surprisingly accurate) and it reliably cycles 220 gr EBR 7.62 x 39 sub sonic ammo