This bowling ball ships PRE-DRILLED. There are 5 sizes and the sizes that we drill are based on the weight of the ball.

X-Small: 6lbs- Ages 8 and under, Small: 8lbs and 9lbs- Ages 8-11 and womens ring size from 8-11, Medium: 10lbs, 11lbs, and 12lbs, Ages 11-15 and Adult Ring size 10 or lower, Large: 13lbs and 14lbs, Mens ring size 10-12 or people with larger hands, X-Large: 15lbs and 16lbs, Mens ring size over 13 or people with extremely large hands.

If you would like a different size drilled for the weight you selected, you must contact us via email as soon as your order is placed with your order number. Pre-Drilled bowling balls cannot be returned or exchanged.

The new Hammer Special Effect is the perfect follow-up to the iconic Effect, Hammer’s most successful High-Performance ball in decades. Building on the proven power of the Huntsman core, featured in the original Effect, the Special Effect takes your game to the next level with HK22-Cohesion Solid, the hottest cover in bowling. This solid cover, crafted with factory compound, delivers exceptional mid-lane motion and an aggressive change of direction. Compared to the original Effect, the Special Effect still provides ease through the front of the lane but is slightly earlier, giving you the edge when there’s oil, and you need a bigger hooking shiny ball. Designed for versatility, the Special Effect is your go-to ball for consistent, high-performance results on a variety of oil patterns.