One theory I've heard is that they were left over from their AK-47 production, but Hungary has exported their AKM's in the tens (hundreds?) of thousands, and all of them seem to have the vented gas tubes.
Hard to believe there would be that many left over parts.
Drilling the ports in the gas tubes requires extra steps in production, so I suppose they must have thought it was desireable for some reason. I would like to know why, too. Extra gas ports doesn't hurt operation, but does it really help anything?
Yes, Drilling the AK gas tube has a few useful functions such as:
1. Reduced carbon fouling in the action ( runs quite a while without cleaning)
2. Reduced gas and heat exiting at the rear of the action by the shooter (especially in armored mounts)
3. Limiting gas impulse duration
Look at the gas systems on RPD, PK, PKM GPM's as a good example they dump the gas out front away from the gunner. Just My Humble Opinion, Artty :smile: