Thread: Reloading subsonic 7.62x39

Originally Posted by Max Headroom

I think that going below 60% of the original max load is unwise for this powder. At that load it's either subsonic or it's not.

Reducing powder loading too far can result in an ugly condition where the powder in the case doesn't burn in the correct way, and you have an explosion known as a flashover. You'll want to google that one.

I'm rather tired of hearing this myth, and the internet's allowed it to propagate far and wide. "Flashover", "detonation" or "secondary explosive effect" or whatever it's attributed to.
Manufacturers and laborotories HAVE TRIED and been UNABLE to replicate it with severely reduced loads.
So with all due respect, Got any facts?

I have a 220gn subsonic load with 2208 for .308.
In the olden-times it was recommended to hold your powder against the primer with dacron or cornmeal. I don't know of anyone who still does this.

As said, start high and work down. Shoot over a chrony and if you get a no-read or your bullet doesn't show up on target STOP and check the barrel, because an obstructed barrel will cause very bad day.
Do your load dev WITHOUT a supressor and check targets for tumbling or keyholing - if there is any, find another projectile.