As the tip of pin exerts more force when compared to head of pin on the same surface area
Point of impact especially at 30 and 40 yards is almost never the same as field points with any broad head. Most broad heads today are quite accurate but in most cases will require some walk back tuning. If all u did was adj poundage you have an arrow spine issue

the tip of the pin is sharp because , less surface area so less of the force will be exerted to stich cloth material .But the head is broad and not sharp so that the surface area is more and so more of the force will have to be exerted to stich cloth material .This is also the reason why we use the sharper end of the pin to pierce into the cloth art first.