Propel™ is a evolutionary coverstock developed by Brunswick to improve the mid-lane and backend traction of the ball on today’s slicker oils and lane surfaces. The Propel coverstock was discovered through testing of new formulation additives and process changes in coverstock manufacturing.
Mechanical Asymmetric Core Engineering. The MACE core has three major benefits: ultra low RG core system to engage the Propel coverstock, high RG differential to aid in traction through heavy oil and high RG asymmetric differential to quicken the response time to friction. Designed as a two-component elliptical core system, the MACE core is dynamically the strongest asymmetric core ever produced for a Brunswick ball.
The Battering Siege™ unites the Propel coverstock and the MACE core to produce a ball motion that is both aggressive in the oil and aggressive on the backend. The Battering Siege is your ball when your game needs help battling heavy oil conditions and poor pin action.
The Battering Siege can be drilled using the standard drilling techniques developed for asymmetric bowling balls.
The unique core shape of each Brunswick ball is used for weights from 14 to 16 pounds. This approach to lightweight ball engineering provides bowlers with consistent ball reaction characteristics across this weight range. The same drilling instructions can be used for 12- and 13-pound balls. This is because Brunswick uses a generic core shape with an RG differential that is close enough to the 14-16 pound shape.