Can someone tell me how much a box of 20rds weighs? I'm trying to figure out how many loose rounds i have.

weigh the whole lot. then weigh a known number of rounds. divide the first number by the second then multiply by the number of rounds in the known quantity and you'll have your number. don't forget to subtract the weight of the container.

Just put a round on the scale (don't ask what the scale is for). Each round is 16.5gx20=330grams. ~matt