Federal’s Vital-Shok Truball Rifled Slug is claimed to be the most accurate slug ever made for smoothbore shotguns. It lived up to that description by punching tight 50mm groups at 50 metres.
WHEN NIOA SENT ME samples of the hogbusting Truball Rifled Slug it was time to borrow a slug gun and see whether they lived up to their reputation. The 70mm loads featured a hollow-pointed leaden slug with diagonally slanted ribs encased in a dark red ribbed shell.
The hollow-based rifled slug is approximately .729 inch in diameter. The hollow cavity in the slug’s base is obviously intended to allow it to obturate as it is driven out of the case and make it a tight fit for the bore. What’s unique, however, is a plastic ball with a diameter of .500 which fits neatly into the base of the slug, but the lower half projects out far enough to enter a recess in the top of the square-topped plastic overpowder cushion wad.
The unique self-centering TruBall locks the slug and wad in alignment as they are forced out of the shell by the expanding powder gases. The ball and the wad, which is .700 inch in diameter, both drop away shortly after the slug leaves the muzzle allowing the slug to continue its path unimpeeded.
It’s certainly a pious idea and according to Federal, the TruBall system punches out 2-inch groups at 50 yards with up to 75- percent improvement. Marked “12ga 2-3/4- inch MAXIMUM” the 438gn slug has a muzzle velocity of 1,600 fps which translates into a hefty 2,490 ft/lbs of muzzle energy.