12G Dark Storm Onyx

12G Dark Storm Onyx Shotgun Ammo

The pinnacle in high performance competition loads

Developed for the most extreme FITASC and Sporting targets, Gamebore’s Dark Storm Onyx builds upon the outstanding performance of our original Dark Storm load, delivering devastating performance and superb patterns at the longest of ranges.

With our new HDP Wad System, which is the Gamebore Wad System design, injection moulded with High Density Polyethylene for use in ultra high performance loads, with built-in Quad Seal technology improving even further the seal produced by a standard plastic wad, for the ultimate in consistency, performance and pattern whilst reducing the felt recoil. 

Diamond Shot Levelled Up

Diamond Shot Xtra is produced and perfected in-house for total quality control. A harder pellet, graded even further for perfection in size and sphericity.

Dark Storm Onyx is an ultra-high performance clay cartridge with a muzzle velocity of 1400 fps at 3ft. Our new, top of the range RS propellant gives the highest performance possible, whilst remaining comfortable on the shoulder. With a nickel plated head for smooth, consistent and reliable ejection.

Diamond Shot Sizes

7.5 2.4mm

Quad Seal

Exclusive four-ring gas seal


Diamond Shot Xtra

Our harder precision lead shot, graded 7 times


HDP Gamebore Wad System

High Density Polyethylene wad especially for ultra high performance loads


The pinnacle in performance with a velocity of 1400fps at 3ft



HDP Gamebore Wad System

HDP Gamebore Wad System

Gamebore's Wad System design injection moulded with High Density Polyethylene for use in ultra high performance loads, with Quad Seal technology further improving the seal generated by the standard plastic wad.

Diamond Shot Xtra

Diamond Shot Xtra

Diamond Shot Xtra is produced and perfected in-house for absolute quality control. A harder pellet than our original Diamond Shot, graded even further.

CX2000 Primer

CX2000 Primer

The most highly consistent and reliable primer available. We use CX2000 Primer throughout our range of shotgun cartridges to give the shooter the utmost reliability and confidence.

HD Hull

HD Hull

High density polymer plastic hull designed to perform in our premium, high performance range. Delivering easy loading and smooth ejection from a case made specifically for these demanding loads.

Ultimate Performance

Ultimate Performance

Developed to ensure each component combines to give their maximum potential and deliver results which are greater than the sum of their parts - simply the cutting edge of performance cartridges.

High Velocity

High Velocity

Cartridges with high velocity are ideal for performance use and demanding disciplines where targets are at range.

Technical performance
Velocity x Distance

The following graph shows the relationship between Velocity (MPS) and Distance (M) for the shot selected from the table below.

Load Oz Shot Size WAD Length mm FPS at 3FT
1 oz 7.5 Plastic QS 20/70mm 1400

Designed & Developed by Gamebore for Gamebore

How the Quad Seal Works

Designed and developed by our R&D division, the unique four-ring design of the Quad Seal gives four times the sealing area of a conventional plastic wad, retaining energy and giving improved performance with a smoother shoot.

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