Evening - 10 lbs of powder, yup, I reckon that would take a heap of shooting and reloading to dispose in the proper manner. W231 is the one I’d try if I was to change powders from Unique. I have heard it’s cleaner burning than Unique.
I’m not sure what powder G’nad uses in his reloading for his sidearms.
.45? Win 231
.38/.357? Unique