Bowling ball core · Brunswick

Brunswick Contra Core

Symmetric Brunswick core

A symmetric core with early rev-up and medium flare, built for medium to heavy oil. Balls with this core are no longer available at BowlersMart.

  • Symmetric
  • RG 2.474
  • Diff 0.047
Brunswick Contra symmetric core shape inside the ball

Specs

RG AT 15 LB

2.474

Early rev-up

Revs soonerRevs later

14% of the reactive and urethane balls we stock have a lower RG.

DIFFERENTIAL AT 15 LB

0.047

Medium flare

Less flareMore flare

49% of the reactive and urethane balls we stock have a lower differential.

MASS BIAS AT 15 LB

None

Symmetric core

Symmetric cores have no mass bias marker to place when drilling.

RG How soon the ball revs up.Differential How much the ball can flare.Mass bias How asymmetric the core is.
Brunswick Contra Core specs by ball weight
Weight RG DifferentialDiff Mass biasMB
16 lb 2.487 0.045 None
15 lbUsed on this page 2.474 0.047 None
14 lb 2.524 0.045 None
13 lb 2.510 0.047 None
12 lb 2.577 0.045 None

Source: Brunswick published specs, as shown on BowlersMart’s original Brunswick Contra core page (2022). RG and differential change with ball weight; use the row for the weight you throw. The highlighted 15 lb row is the one used on this page.

Looking for a ball like your Brunswick Contra?

Balls with the Brunswick Contra Core are no longer available at BowlersMart. These in-stock balls have the closest RG and differential.

Track Theorem Delta Bowling Ball

Track Theorem Delta

Track Super Response Hybrid HK22 Reactive

Medium to heavy oil

Sale price $174.95 Regular price $279.95In stock
Motiv Sigma Tour Pearl Bowling Ball

Motiv Sigma Tour Pearl

Motiv Atomic Propulsion Pearl Reactive

Medium to heavy oil

Sale price $204.95 Regular price $289.95In stock
Brunswick Energize Bowling Ball

Brunswick Energize

Brunswick HK22C EVO Hybrid Reactive

Medium to heavy oil

Sale price $164.95 Regular price $249.95In stock
Ebonite Game Breaker 5 Hybrid Bowling Ball

Ebonite Game Breaker 5 Hybrid

Ebonite GB 12.7 Hybrid Reactive

Medium to heavy oil

Sale price $144.95 Regular price $229.95In stock
Hammer Hammerhead Pearl Bowling Ball

Hammer Hammerhead Pearl

Hammer Aggression Pearl Reactive

Medium oil

Sale price $149.95 Regular price $249.95In stock
Hammer Full Effect Bowling Ball

Hammer Full Effect

Hammer HK22C2 Hybrid Reactive

Medium to heavy oil

Sale price $194.95 Regular price $279.95In stock

Balls with the Brunswick Contra Core

None of the 5 balls with the Brunswick Contra Core are in stock at BowlersMart right now.

Show 5 balls no longer available at BowlersMart
More bowling balls with the Brunswick Contra Core
Ball Cover First seen
Brunswick Fearless Bowling Ball Brunswick Relentless Solid Reactive October 2018
Brunswick Hero Bowling Ball Brunswick Activator Plus 2.0 Pearl Reactive July 2019
Brunswick Hero Solid Bowling Ball Brunswick Activator Plus 2.0 Solid Reactive October 2020
Brunswick Attitude Pearl Bowling Ball Brunswick Activator Plus 3.0 Pearl Reactive May 2022
Brunswick Attitude Control Bowling Ball Brunswick Pearl Urethane May 2022

Where the Brunswick Contra sits

Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.

Storm Element Tour A.I. Core, RG 2.470, diff 0.035DV8 Larceny Core, RG 2.471, diff 0.028DV8 Renegade Core, RG 2.499, diff 0.040Track I-Core Gen4, RG 2.480, diff 0.053Brunswick Vintage Light Bulb Low RG Core, RG 2.568, diff 0.032Brunswick Dual Centric Core, RG 2.509, diff 0.047Ebonite Big Time Core, RG 2.508, diff 0.054Hammer Stacked LED Core, RG 2.545, diff 0.047Hammer Vindicator Core, RG 2.474, diff 0.053Radical Vexed Variant Asymmetric Core, RG 2.490, diff 0.045Radical Modified Intel Symmetric Core, RG 2.483, diff 0.032Motiv Affliction V2 Core, RG 2.480, diff 0.055900 Global Conduit A.I. Core, RG 2.590, diff 0.050Roto Grip GEM A.I. Core, RG 2.490, diff 0.057Hammer Obsession Tour Core, RG 2.469, diff 0.034Hammer Super Offset Core, RG 2.524, diff 0.053Hammer Gas Mask Core, RG 2.500, diff 0.058Ebonite Turbo Core, RG 2.517, diff 0.040Ebonite Centrex Symmetrical Mass Bias Core, RG 2.466, diff 0.056Motiv Excel Core, RG 2.550, diff 0.030Motiv Detonator Core, RG 2.470, diff 0.055Storm Solarion A.I. Core, RG 2.480, diff 0.054SWAG Insanity Symmetric Core, RG 2.520, diff 0.034SWAG Fusion Core, RG 2.540, diff 0.036SWAG Watcher Symmetric Core, RG 2.510, diff 0.048SWAG Dragon Asymmetric Core, RG 2.490, diff 0.050SWAG Executioner Asymmetric Core, RG 2.500, diff 0.051Motiv Predator V2 Core, RG 2.470, diff 0.054Storm C3 Centripetal Control Core, RG 2.490, diff 0.029Roto Grip Rondure MaxD Core, RG 2.500, diff 0.058Hammer Vibe Core, RG 2.510, diff 0.042Hammer Aftermath Core, RG 2.520, diff 0.052Brunswick Alert Core, RG 2.478, diff 0.037Brunswick Rampart Core, RG 2.502, diff 0.051DV8 Collision Core, RG 2.462, diff 0.052Radical Evil Eye Symmetric Core, RG 2.495, diff 0.046Ebonite Iron Fist V2 Core, RG 2.473, diff 0.053Radical No Doubt Symmetric Core, RG 2.485, diff 0.051Storm Surge Core, RG 2.580, diff 0.024Roto Grip Hyped UP Core, RG 2.500, diff 0.042Roto Grip Morph-Wing Core, RG 2.510, diff 0.051Brunswick Fury Core, RG 2.524, diff 0.038Roto Grip Hustle Core, RG 2.530, diff 0.030900 Global Blast A.I. Core, RG 2.470, diff 0.055900 Global Strobe A.I. Core, RG 2.510, diff 0.052Radical Guru Core, RG 2.503, diff 0.044Track I-CORE 3.0, RG 2.486, diff 0.056DV8 Unholy Core, RG 2.504, diff 0.051Brunswick Infinity Core, RG 2.521, diff 0.051Storm Catalyst A.I. Core, RG 2.480, diff 0.053Hammer Gauntlet Core, RG 2.501, diff 0.050Hammer Raw Hammer Core, RG 2.537, diff 0.038Storm Atmos A.I. Core, RG 2.530, diff 0.042Storm Booster Core, RG 2.540, diff 0.046Track Shuttle Core, RG 2.480, diff 0.040Brunswick Light Bulb Core, RG 2.524, diff 0.030Radical Sneak Attack Core, RG 2.544, diff 0.036Motiv Gear Core, RG 2.480, diff 0.034Hammer Huntsman Core, RG 2.470, diff 0.050Hammer Super LED Core, RG 2.632, diff 0.034DV8 Dualistic Core, RG 2.496, diff 0.045Radical Vexed Asymmetric Core, RG 2.498, diff 0.036Motiv Quadfire Core, RG 2.550, diff 0.043Track Stealth Core, RG 2.482, diff 0.056Brunswick Tiered Hexagon Core, RG 2.540, diff 0.045Columbia 300 Piranha Core, RG 2.554, diff 0.043Storm Torsion A.I. Core, RG 2.470, diff 0.050Storm Element Max A.I. Core, RG 2.470, diff 0.055Storm Radius Core, RG 2.610, diff 0.020Roto Grip Rondure Tour X Core, RG 2.480, diff 0.034SWAG Unreal Core, RG 2.510, diff 0.047SWAG Craze Core, RG 2.520, diff 0.030SWAG Serpent Asymmetric Core, RG 2.510, diff 0.048Radical Torpedo Asymmetric Core, RG 2.480, diff 0.052Motiv Overload Core, RG 2.480, diff 0.050DV8 Duality Core, RG 2.480, diff 0.036Radical Outer Limits Asymmetric Core, RG 2.499, diff 0.051Motiv Apex Predator Core, RG 2.520, diff 0.055Brunswick Danger Zone Core, RG 2.501, diff 0.048Storm RAD-TQ Core, RG 2.560, diff 0.051Storm Velocity Core, RG 2.480, diff 0.051Hammer Modified LED Core, RG 2.586, diff 0.027Epic Spark Core, RG 2.540, diff 0.049Motiv Hadron Dual Density Core, RG 2.500, diff 0.045Track Criterion ID Core, RG 2.496, diff 0.047Ebonite Entity Core, RG 2.515, diff 0.052Roto Grip Rocker A.I. Core, RG 2.480, diff 0.050Motiv Flux Core, RG 2.570, diff 0.015DV8 Mantra Core, RG 2.498, diff 0.047Hammer Gas Mask Low Diff Core, RG 2.500, diff 0.034Roto Grip RST A.I. Core, RG 2.520, diff 0.055Motiv Impulse V2 Core, RG 2.550, diff 0.050SWAG APX V1 Core, RG 2.500, diff 0.042SWAG Judge Core, RG 2.490, diff 0.052900 Global Magna A.I. Core, RG 2.490, diff 0.044KR Strikeforce Launch Core, RG 2.530, diff 0.047900 Global Ellipse Asymmetric A.I. Core, RG 2.480, diff 0.050Motiv Halogen Core, RG 2.550, diff 0.037Storm C3 A.I. Core, RG 2.480, diff 0.031Motiv Gear APG Core, RG 2.470, diff 0.036Radical Snapshot Symmetric Core, RG 2.523, diff 0.050Hammer High Rev Offset Core, RG 2.489, diff 0.053Hammer Huntsman Tour Core, RG 2.472, diff 0.036Hammer LED Core, RG 2.650, diff 0.015Storm Inverted Fe2 Core, RG 2.570, diff 0.046Storm Capacitor Core, RG 2.570, diff 0.022Motiv Sigma Core (pictured: Motiv Sigma Tour Pearl Bowling Ball)1Ebonite Enhanced V2 Core (pictured: Ebonite Game Breaker 5 GB5 Bowling Ball)2Hammer Spheroid Core (pictured: Hammer Hammerhead Pearl Bowling Ball)3Track MC2 Asym Core (pictured: Track Theorem Pearl Bowling Ball)4Brunswick Zone Asymmetric Core (pictured: Brunswick Energize Bowling Ball)5Columbia 300 Pulse PowerCOR Core (pictured: Columbia 300 Pulse Bowling Ball)6Brunswick Contra Core (pictured: Brunswick Attitude Pearl Bowling Ball)EARLY REV-UPMID-LANELATER REV-UPHIGH FLAREMEDIUMLOW FLARE2.442.482.522.562.602.642.680.0100.0200.0300.0400.0500.060RG at 15 lbDifferential at 15 lb← Revs up soonerRevs up later →More flare ↑Less flare ↓

Nearest cores, zoomed in

Hover or tap a dot for that core’s numbers. Click a dot to open its page. Drag to move around when zoomed in. The same RG and differential do not guarantee the same ball motion.

This core 1 Nearest cores Other cores

Nearest cores to the Brunswick Contra Core
Core Brand Shape RG Diff vs this core
Motiv Sigma Tour Pearl Bowling Ball1Motiv Sigma CorePictured: Motiv Sigma Tour Pearl
 Motiv Symmetric 2.470 0.047 RG −0.004 · Diff 0.000
Ebonite Game Breaker 5 GB5 Bowling Ball2Ebonite Enhanced V2 CorePictured: Ebonite Game Breaker 5 GB5
 Ebonite Symmetric 2.480 0.048 RG +0.006 · Diff +0.001
Hammer Hammerhead Pearl Bowling Ball3Hammer Spheroid CorePictured: Hammer Hammerhead Pearl
 Hammer Symmetric 2.480 0.048 RG +0.006 · Diff +0.001
Track Theorem Pearl Bowling Ball4Track MC2 Asym CorePictured: Track Theorem Pearl
 Track Asymmetric 2.473 0.046 RG −0.001 · Diff −0.001
Brunswick Energize Bowling Ball5Brunswick Zone Asymmetric CorePictured: Brunswick Energize
 Brunswick Asymmetric 2.478 0.048 RG +0.004 · Diff +0.001
Columbia 300 Pulse Bowling Ball6Columbia 300 Pulse PowerCOR CorePictured: Columbia 300 Pulse
 Columbia 300 Symmetric 2.468 0.045 RG −0.006 · Diff −0.002

Matches use 15 lb RG and differential.

Drilling and tools

Brunswick drill sheetsLayout guides for symmetric and asymmetric ballsDual angle converterTurn a pin to PAP layout into a dual angle layout

Turn on JavaScript to compare with your ball.Balls with the Brunswick Contra CoreNone of the 5 balls with the Brunswick Contra Core are in stock at BowlersMart right now.Show 5 balls no longer available at BowlersMartMore bowling balls with the Brunswick Contra CoreBallCoverFirst seenBrunswick Fearless Bowling BallBrunswick Relentless Solid ReactiveOctober 2018Brunswick Hero Bowling BallBrunswick Activator Plus 2.0 Pearl ReactiveJuly 2019Brunswick Hero Solid Bowling BallBrunswick Activator Plus 2.0 Solid ReactiveOctober 2020Brunswick Attitude Pearl Bowling BallBrunswick Activator Plus 3.0 Pearl ReactiveMay 2022Brunswick Attitude Control Bowling BallBrunswick Pearl UrethaneMay 2022Where the Brunswick Contra sitsEach dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.All coresSymmetricAsymmetricBrunswick onlyAny brand900 GlobalBrunswickColumbia 300DV8EboniteEpicHammerKR StrikeforceMotivRadicalRoto GripSWAGStormTrack+−ResetZoom to this coreStorm Element Tour A.I. Core, RG 2.470, diff 0.035DV8 Larceny Core, RG 2.471, diff 0.028DV8 Renegade Core, RG 2.499, diff 0.040Track I-Core Gen4, RG 2.480, diff 0.053Brunswick Vintage Light Bulb Low RG Core, RG 2.568, diff 0.032Brunswick Dual Centric Core, RG 2.509, diff 0.047Ebonite Big Time Core, RG 2.508, diff 0.054Hammer Stacked LED Core, RG 2.545, diff 0.047Hammer Vindicator Core, RG 2.474, diff 0.053Radical Vexed Variant Asymmetric Core, RG 2.490, diff 0.045Radical Modified Intel Symmet

From Brunswick’s description

Questions bowlers ask

What is the RG of the Brunswick Contra Core?

At 15 lb the Brunswick Contra Core has an RG of 2.474. It ranges from 2.474 to 2.577 across the listed weights.

What is the 14 lb RG of the Brunswick Contra Core?

At 14 lb the RG is 2.524.

What is the differential of the Brunswick Contra Core?

At 15 lb the differential is 0.047. This is a symmetric core, so mass bias is not applicable.

Which bowling balls use the Brunswick Contra Core?

Brunswick Fearless Bowling Ball, Brunswick Hero Bowling Ball, Brunswick Hero Solid Bowling Ball, Brunswick Attitude Pearl Bowling Ball, Brunswick Attitude Control Bowling Ball. 0 are in stock now.

Can I still buy a ball with the Brunswick Contra Core?

Balls with this core are currently unavailable at BowlersMart. Closest in-stock alternatives by RG and differential include Track Theorem Delta Bowling Ball, Motiv Sigma Tour Pearl Bowling Ball, Brunswick Energize Bowling Ball, Ebonite Game Breaker 5 Hybrid Bowling Ball, Hammer Hammerhead Pearl Bowling Ball, Hammer Full Effect Bowling Ball.

How do the Brunswick Contra Core specs change by weight?

At 16 lb: RG 2.487, differential 0.045. At 12 lb: RG 2.577, differential 0.045.

How does the Brunswick Contra Core compare with my ball?

Type the ball you throw into the Compare with your ball box on this page. It shows the RG and differential side by side and saves your bag for every core page.

Sources and method

Specs. Brunswick published specs, as shown on BowlersMart’s original Brunswick Contra core page (2022), as published by the manufacturer.

Baseline. The baseline is 212 in-stock, published reactive and urethane balls. Plastic and polyester covers, 2-piece, 3-piece and pancake cores, missing covers and missing RG or differential values are excluded.

Percentiles. Percentiles are the share of baseline balls with a strictly lower or higher value; ties are not counted.

Nearest cores. Nearest cores are ranked by distance on standardized 15 lb RG and differential, with the same symmetric or asymmetric shape preferred among near ties (distance bands of 0.1).

Mass bias. Mass bias is compared among asymmetric balls with numeric mass bias only.

Updated. Catalog and page updated 2026-10-16.

Next lesson

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