Bowling ball core · Hammer
Hammer Gauntlet Core
The core inside the Hammer Gauntlet line
An asymmetric core with mid-lane rev-up and medium flare, built for medium to heavy oil. 1 of the 10 balls with this core are in stock at BowlersMart.
- Asymmetric
- RG 2.501
- Diff 0.050
- MB 0.012

Specs
RG AT 15 LB
2.501
Mid-lane rev-up
52% of the reactive and urethane balls we stock have a lower RG.
DIFFERENTIAL AT 15 LB
0.050
Medium flare
62% of the reactive and urethane balls we stock have a lower differential.
MASS BIAS AT 15 LB
0.012
Mild asymmetry
11% of the asymmetric reactive and urethane balls we stock have a lower mass bias.
| Weight | RG | DifferentialDiff | Mass biasMB |
|---|---|---|---|
| 16 lb | 2.512 | 0.044 | 0.011 |
| 15 lbUsed on this page | 2.501 | 0.050 | 0.012 |
| 14 lb | 2.517 | 0.050 | 0.012 |
| 13 lb | 2.597 | 0.041 | 0.014 |
| 12 lb | 2.593 | 0.041 | 0.014 |
Source: Hammer published specs, as listed on the Spawn product page. 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.
Balls with the Hammer Gauntlet Core
1 of the 10 balls with the Hammer Gauntlet Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

Hammer HK22 C2 Solid Reactive
Medium to heavy oil
Show 9 balls no longer available at BowlersMart
| Ball | Cover | First seen |
|---|---|---|
| Hammer Gauntlet Bowling Ball | Hammer Semtex Solid CFI Reactive | January 2017 |
| Hammer Gauntlet Fury Overseas Bowling Ball | Hammer Semtex Pearl CFI Reactive | October 2017 |
| Hammer Gauntlet Axe Overseas Bowling Ball | Hammer Semtex Slayer II CFI Reactive | July 2018 |
| Hammer Gauntlet Extra Overseas Bowling Ball | Hammer Semtex Solid CFI Reactive | July 2018 |
| Hammer Gauntlet Caesar Overseas Bowling Ball | Hammer Semtex Slayer Pearl CFI Reactive | November 2018 |
| Hammer Gauntlet Knight Overseas Bowling Ball | Hammer Semtex Slayer II CFI Reactive | November 2018 |
| Hammer Gauntlet Thor Overseas Bowling Ball | Hammer Semtex Slayers 3 CFI Reactive | April 2019 |
| Hammer Platinum Gauntlet Silver Overseas Bowling Ball | Hammer Aggression Bite Pearl Reactive | August 2019 |
| Hammer Platinum Red Wine Gauntlet Bowling Ball | Hammer Aggression Bite Pearl Reactive | November 2019 |
Where the Hammer Gauntlet sits
Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
Nearest cores, zoomed in
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
This core 1 Nearest cores Other cores
| Core | Brand | Shape | RG | Diff | vs this core |
|---|---|---|---|---|---|
|
|
Brunswick | Asymmetric | 2.502 | 0.051 | RG +0.001 · Diff +0.001 |
|
|
SWAG | Asymmetric | 2.500 | 0.051 | RG −0.001 · Diff +0.001 |
|
|
Radical | Asymmetric | 2.499 | 0.051 | RG −0.002 · Diff +0.001 |
|
|
DV8 | Asymmetric | 2.504 | 0.051 | RG +0.003 · Diff +0.001 |
|
|
Brunswick | Symmetric | 2.501 | 0.048 | RG 0.000 · Diff −0.002 |
|
|
Roto Grip | Asymmetric | 2.510 | 0.051 | RG +0.009 · Diff +0.001 |
Matches use 15 lb RG and differential.
Drilling and tools
Turn on JavaScript to compare with your ball.Balls with the Hammer Gauntlet Core1 of the 10 balls with the Hammer Gauntlet Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.
Questions bowlers ask
What is the RG of the Hammer Gauntlet Core?
At 15 lb the Hammer Gauntlet Core has an RG of 2.501. It ranges from 2.501 to 2.597 across the listed weights.
What is the 14 lb RG of the Hammer Gauntlet Core?
At 14 lb the RG is 2.517.
What is the differential of the Hammer Gauntlet Core?
At 15 lb the differential is 0.050. The mass bias is 0.012.
Which bowling balls use the Hammer Gauntlet Core?
Hammer Spawn Bowling Ball, Hammer Gauntlet Bowling Ball, Hammer Gauntlet Fury Overseas Bowling Ball, Hammer Gauntlet Axe Overseas Bowling Ball, Hammer Gauntlet Extra Overseas Bowling Ball. 1 are in stock now.
How do the Hammer Gauntlet Core specs change by weight?
At 16 lb: RG 2.512, differential 0.044, mass bias 0.011. At 12 lb: RG 2.593, differential 0.041, mass bias 0.014.
How does the Hammer Gauntlet 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. Hammer published specs, as listed on the Spawn product page, 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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