Wow! C-300. There's a blast from my past. No pun intended. Story for ya... If you're in a hurry you may just want to skip the rest.
As a budding 12 year old reloader in the NWT in the early '70's I score a cheap keg of C300. Not sure how much it held but it was slightly smaller then a 5 gallon pail.
I was about to reload 20 ga., and the guy I buy it from says I need 14.4 grains. But I have no scale, and there are no other reloaders in my small town who have one. Hhmm... A popular pain killer at the time (Anacin? Excedrin?) used to advertise in their TV commercial that each pill held 7 gr. of pain reliever. Eureka! Two pills must therefore weigh 14gr., right? So I buy a bottle (I'm 12 years old!) and take 2 pills and some C300 to my school, where I use the science class beam balance scale to measure out what should be 14gr. Close enough. I make a powder scoop from an empty rifle brass and proceed over the next 5 or 6 years to use up the keg. Thousands of rounds, all through my trusty Savage 24 22/20ga. It was nothing to fire a few hundred rounds per day. It breaks at last once an is repaired. When I leave the north I sell the gun, but it is WELL used. You could shake it and it would rattle, literally.
Years later, just for giggles, I weigh two of the pills. Nineteen grains. What the commercial failed to mention was that while there may be 7 grains of pain killer per pill, there's also a few grains of binder, to hold it together. God does indeed look after stupid people, and Savage did indeed make tough guns.