Let me clarify my previous statement.
1000 rounds of .223 takes up approximately the same space as 3 bags of sugar.
They are much heavier than 15 pounds.
1000 rounds of 223 are normally shipped in a box that is 8-1/2”x11”x5”. About the same as a large shoebox, or two reams of paper.
Weighs about 27 lbs.