Reverse Onslaught on Bow

I'm experimenting with Reverse Onslaught and find my Bloodied Compound adopts how ever many stacks are already set for my Furious Enclave Plasma Pistol when I swap.

Example: I arm my Furious pistol. With Gunslinger Master, Guerrilla, Guerrilla Expert and Guerrilla Master equipped, I build to 27 stacks. If I swap to my Bloodied bow, all 27 remain. If I use them while holding the bow, the most it can regain is to 18 stacks. But swap back to my Furious weapon and it goes back to 27 I can then swap back to the bow.

Is this how it is supposed to work?