Nielsen 6.35 mm HPFB 43.5 grain (.250) slugs are swaged from soft lead. By swaging them and not forging, a far better consistency is achieved. Not only the consistency of the material is better, the slugs themselves are also extremely uniform in shape and size, making for a high level of accuracy.
The soft lead and hollow point design give these Nielsen 6.35 mm HPFB 43.5 grain (.250) slugs a very rapid expansion. The ballistic coefficient is 0.110.