410 slugs (1/4 oz.) are only about 1/2 the weight of the shot in a 410 field load (1/2 oz or more). In comparison 12 gauge slugs weigh about the same amount as the shot in field load. 20 gauge slugs are the same, a slug weighs about the same as the shot in field load. I'm dazed and confused why their should be such a difference.