Founds some Chinese rifle grenade info to share.
Type90 40mm Rifle Grenade Variants left to right:
-DQP1-40mm armour piercing
-DQS1-40mm High Explosive Fragmentation
-DQF1-40mm Smoke
-DQR1-40mm incendiary
-DQD1-40mm Timing AT (not shown)
The latest compatible grenades are these Type03 40mm Rifle Grenade rounds.
Supposedly the Type 03 grenades can be fired with service ammo, while the Type 90 grenades needed special cartridges.
what's less clear is whether these definitely fit a type 81. The DEFINITELY fit the QBZ-95, but in that case, they just slip over the flash hider. I think they would fit though looking at the long cavity in the cutaway diagrams.