just recieved a pistol chamber for my redding b.r. powder measure. ran 2 tests with bulleseye powder. with the pistol chamber 10 throws measured 4.0 to 4.1 with one measuring 3.9. with the large chamber; the first 3 were 4.0 to 4.1. after that the next 15 measured from 3.1 to 3.5. i don't know what caused the first 3 to be so high. but excluding the first 3; i'll be using the small chamber for pistol powders. i have a belding and mull measure that i will test some day. oh, i forgot i have an older lyman 55. it includes a small chamber for light charges.