The wife is diabetic and her test strip containers are the perfect size to hold black powder for my golf ball mortar. The 'One Touch' brand holds up to 250 grains of powder. She gives me about 3 every two weeks, so they add up fast.
I also shoot 1 5/8" inch PVC filled with concrete outta my golf ball mortar, so, if anyone is tired of just blasting golf balls, give it a try.