I would hardly never get pass throughs usings mechanicals, maybe like 25%. So far with slick tricks i'm 2 for 2 on pass throughs. One of the shots was exactly like one from last year, same stand, same yardage, same sized buck and my spitfire only penetrated 18 or so inches and my slicktricks blew right though. Mechaniclas open a nice hole but are not great when it comes to penetration, especially on angled shots.