Thread: Loading 7.62x39 subsonic from steel cased factory ammo

I'm just curious - still haven't decided to get into reloading yet - but let's say I wanted to make a batch of subsonic load out of factory steel cased ammo with 125grn projectiles, for used in a 16" suppressed bolt gun.

Could I pull the projectile and then:

1. Reduce the powder charge and use some polyester wadding to keep the charge against the flash hole; OR
2. Load with a more appropriate powder that uses the case capacity but keeps the load subsonic

(Not intending to reload the steel case after firing.)

The intention behind this is to keep the overall component cost low, and achieve subsonic for close range pest control <100m.
I'm aware of 300BLK but given the availability of 7.62x39 I thought this idea might have some merit.

Let me know if this is a bad idea / why / or possible?