A heavyweight .177 JSB Knock Slug, extremely favourable Ballistic Coefficient of 0.066, ensuring a flat trajectory and excellent energy retention at 13.43 gr with a body diameter of 4.52 mm. A distinct hollow point, manufactured in the soft lead JSB is renowned for, designed with a well recessed base, producing wicked terminal expansion and penetration on impact, highly accurate. These are designed to work primarily in High Power Airguns, ( FAC in the UK ). Recommended Use: Hunting/Pest Control Long Range 100+ m