JSB Knock Out 5.5 mm 25.39 grain slugs didn’t get their name for being lightweights. With 25.39 grain these 5.5 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 5.5 mm 25.39 grain slugs is 0.084.