Bowling ball core · Brunswick

Brunswick Portal X Core

The core inside the Brunswick Defender line

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

  • Asymmetric
  • RG 2.473
  • Diff 0.054
  • MB 0.015
Brunswick Portal X symmetric core shape inside the ball

Specs

RG AT 15 LB

2.473

Early rev-up

Revs soonerRevs later

13% of the reactive and urethane balls we stock have a lower RG.

DIFFERENTIAL AT 15 LB

0.054

High flare

Less flareMore flare

83% of the reactive and urethane balls we stock have a lower differential.

MASS BIAS AT 15 LB

0.015

Mild asymmetry

MilderStronger

24% of the asymmetric reactive and urethane balls we stock have a lower mass bias.

RG How soon the ball revs up.Differential How much the ball can flare.Mass bias How asymmetric the core is.
Brunswick Portal X Core specs by ball weight
Weight RG DifferentialDiff Mass biasMB
16 lb 2.489 0.046 0.013
15 lbUsed on this page 2.473 0.054 0.015
14 lb 2.498 0.054 0.015
13 lb 2.597 0.041 0.014
12 lb 2.593 0.041 0.014

Source: Brunswick published specs, as shown on BowlersMart’s original Brunswick Portal X 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 Defender?

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

Motiv Jackal Ghost V2 Bowling Ball

Motiv Jackal Ghost V2

Motiv Leverage HFS Reactive

Heavy oil, medium to heavy oil

Sale price $219.95 Regular price $289.95In stock
Ebonite Spartan Pearl Bowling Ball

Ebonite Spartan Pearl

Ebonite HK22C2 Optimize Pearl Reactive

Heavy oil, medium oil

Sale price $189.95 Regular price $279.99In stock
Hammer Reckoning Bowling Ball

Hammer Reckoning

Hammer HK22C2 Solid Reactive

Heavy oil

Sale price $194.95 Regular price $279.95In stock
Motiv Forge Fuel Bowling Ball

Motiv Forge Fuel

Motiv Leverage MXT Solid Reactive

Medium to heavy oil

Sale price $204.95 Regular price $289.95In stock
900 Global Vengeance Returns Bowling Ball

900 Global Vengeance Returns

900 Global RB 91 Hybrid Reactive

Medium to heavy oil

Sale price $184.95 Regular price $299.95In stock
Storm Ion Max Pearl Bowling Ball

Storm Ion Max Pearl

Storm NRG Pearl Reactive

Medium to heavy oil

Sale price $189.95 Regular price $249.95In stock

Balls with the Brunswick Portal X Core

None of the 4 balls with the Brunswick Portal X Core are in stock at BowlersMart right now.

Show 4 balls no longer available at BowlersMart
More bowling balls with the Brunswick Portal X Core
Ball Cover First seen
Brunswick Ultimate Defender Bowling Ball Brunswick A.C.T 3.0 Hybrid Reactive February 2024
Brunswick Defender Aegis Overseas Bowling Ball Brunswick A.C.T 3.0 Pearl Reactive April 2023
Brunswick Defender Hybrid Bowling Ball Brunswick A.C.T 3.0 Hybrid Reactive September 2022
Brunswick Defender Bowling Ball Brunswick A.C.T. 3.0 Solid Reactive February 2022

Where the Brunswick Portal X 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 0.047Radical 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 0.030Storm 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 0.051Storm 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 0.052Track MC2 Asym Core, RG 2.473, diff 0.046Radical Evil Eye Symmetric Core, RG 2.495, diff 0.046Radical 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 0.038Motiv Sigma Core, RG 2.470, diff 0.047Roto Grip Hustle Core, RG 2.530, diff 0.030900 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 0.034Ebonite Enhanced V2 Core, RG 2.480, diff 0.048DV8 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 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 0.036Hammer Spheroid Core, RG 2.480, diff 0.048Radical 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 0.047Brunswick Zone Asymmetric Core, RG 2.478, diff 0.048Ebonite 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 0.044Columbia 300 Pulse PowerCOR Core, RG 2.468, diff 0.045KR 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 Predator V2 Core (pictured: Motiv Jackal Onyx Bowling Ball)1Ebonite Iron Fist V2 Core (pictured: Ebonite Spartan Pearl Bowling Ball)2Hammer Vindicator Core (pictured: Hammer Reckoning Bowling Ball)3Storm Element Max A.I. Core (pictured: Storm Ion Max Bowling Ball )4900 Global Blast A.I. Core (pictured: 900 Global Vengeance Bowling Ball)5Motiv Detonator Core (pictured: Motiv Steel Forge Bowling Ball)6Brunswick Portal X Core (pictured: Brunswick Ultimate Defender 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.

Same family: Brunswick Portal Core

This core 1 Nearest cores Other cores

Nearest cores to the Brunswick Portal X Core
Core Brand Shape RG Diff vs this core
Motiv Jackal Onyx Bowling Ball1Motiv Predator V2 CorePictured: Motiv Jackal Onyx
 Motiv Asymmetric 2.470 0.054 RG −0.003 · Diff 0.000
Ebonite Spartan Pearl Bowling Ball2Ebonite Iron Fist V2 CorePictured: Ebonite Spartan Pearl
 Ebonite Asymmetric 2.473 0.053 RG 0.000 · Diff −0.001
Hammer Reckoning Bowling Ball3Hammer Vindicator CorePictured: Hammer Reckoning
 Hammer Asymmetric 2.474 0.053 RG +0.001 · Diff −0.001
Storm Ion Max Bowling Ball 4Storm Element Max A.I. CorePictured: Storm Ion Max Bowling Ball 
 Storm Asymmetric 2.470 0.055 RG −0.003 · Diff +0.001
900 Global Vengeance Bowling Ball5900 Global Blast A.I. CorePictured: 900 Global Vengeance
 900 Global Symmetric 2.470 0.055 RG −0.003 · Diff +0.001
Motiv Steel Forge Bowling Ball6Motiv Detonator CorePictured: Motiv Steel Forge
 Motiv Symmetric 2.470 0.055 RG −0.003 · Diff +0.001

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 Portal X CoreNone of the 4 balls with the Brunswick Portal X Core are in stock at BowlersMart right now.Show 4 balls no longer available at BowlersMartMore bowling balls with the Brunswick Portal X CoreBallCoverFirst seenBrunswick Ultimate Defender Bowling BallBrunswick A.C.T 3.0 Hybrid ReactiveFebruary 2024Brunswick Defender Aegis Overseas Bowling BallBrunswick A.C.T 3.0 Pearl ReactiveApril 2023Brunswick Defender Hybrid Bowling BallBrunswick A.C.T 3.0 Hybrid ReactiveSeptember 2022Brunswick Defender Bowling BallBrunswick A.C.T. 3.0 Solid ReactiveFebruary 2022Where the Brunswick Portal X 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 coreDV8 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 0.047Radical 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 0.055Storm Element Tour A.I. Core, RG 2.470, diff 0.035900 Global Conduit A

From Brunswick’s description

Questions bowlers ask

What is the RG of the Brunswick Portal X Core?

At 15 lb the Brunswick Portal X Core has an RG of 2.473. It ranges from 2.473 to 2.597 across the listed weights.

What is the 14 lb RG of the Brunswick Portal X Core?

At 14 lb the RG is 2.498.

What is the differential of the Brunswick Portal X Core?

At 15 lb the differential is 0.054. The mass bias is 0.015.

Which bowling balls use the Brunswick Portal X Core?

Brunswick Ultimate Defender Bowling Ball, Brunswick Defender Aegis Overseas Bowling Ball, Brunswick Defender Hybrid Bowling Ball, Brunswick Defender Bowling Ball. 0 are in stock now.

Can I still buy a ball with the Brunswick Portal X Core?

Balls with this core are currently unavailable at BowlersMart. Closest in-stock alternatives by RG and differential include Motiv Jackal Ghost V2 Bowling Ball, Ebonite Spartan Pearl Bowling Ball, Hammer Reckoning Bowling Ball, Motiv Forge Fuel Bowling Ball, 900 Global Vengeance Returns Bowling Ball, Storm Ion Max Pearl Bowling Ball.

How do the Brunswick Portal X Core specs change by weight?

At 16 lb: RG 2.489, differential 0.046, mass bias 0.013. At 12 lb: RG 2.593, differential 0.041, mass bias 0.014.

How does the Brunswick Portal X 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 Portal X 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.

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