JSB Knock Out HP 4.5 mm (.178) 13.43 grain slugs didn’t get their name for being lightweights. With an individual weight of 13.43 grain these 4.5 mm slugs are heavyweights for sure. Thanks to the hollow point and the soft lead JSB is known for, these slugs offer a very good expansion on impact. The ballistic coefficient of these JSB Knock Out 4.5 mm (.178) 13.43 grain slugs is 0.066. The exact size of these slugs is .178 and one package contains four hundred JSB Knock Out HP 4.5 mm (.178) 13.43 grain slugs.