Actually, that's a good idea. I forgot about that.
But fundamentally, there are better options out there than suppressing a krink, especially one that is just a vanilla configuration standalone gun that you've already built.
Keep in mind that the vast majority of them are not going to have the twist rate for heavy subsonic projectiles, and 7.62x39 doesn't have as wide a selection as the cartridges based on 308 diameter projectiles. And what projectiles there are for the 311 diameter tend to be blunter and have lower BC.
Again, we're back to 300 BLK, which is designed from the ground up to fit AR mags, do both supersonic and subsonic well and work with a regular direct impingement gas system.