- Shim

First Impressions
The Big Bowling Shim comes with the symmetrical Powder Keg Core paired with the P5 Reactive Cover in a pearl version. The specs show a 2.468 RG, a 0.040 differential, and a factory finish of 2000 grit polished. The Shim's color scheme shines in Platinum/Blue and offers a flare potential of 3-4 inches in the medium range. The P5 Reactive surface stands for "Predictable" with a hook rating of 5 on a scale of 1 to 10, which points to balanced performance.
Comparison
The very low RG allows the ball to read early, while the P5 Reactive cover simultaneously carries it down the lane and creates an even motion from start to finish. Compared to more aggressive asymmetric balls like the Storm Phaze II, the Shim shows a more predictable reaction with less extreme backend behavior. The unique dual-pyramidal design with a central extension creates a late tip with a readable flip, which sets it apart from classic benchmark balls like the Storm IQ Tour. Its hook characteristics place it between milder options like the Brunswick Rhino and stronger premium-class performance balls.
On the Lanes
Sometimes you need a late move to play the Shim and get explosive results where it counts. The ball is especially suited if you throw at medium speed and are looking for a controlled yet hard-hitting reaction on medium oil volumes. The Powder Keg Core is aptly named: like a real powder keg, the fuse is slow and steady, but with explosive results at the pins. For transition phases during longer blocks, the Shim's balanced construction should provide reliable carry performance. Its medium aggressiveness makes it a solid choice for league bowlers who need a versatile ball for changing lane conditions.