Gun test: Gunpower Stealth MKIII

‘Unusual, space-age, ray-gun lookalikes …’ it’s all been said about Gunpower, yet these highly original pre-charged airguns have certainly stood the test of time. Mark Camoccio puts the Stealth MKIII under the spotlight…

Modular

'Modular' is the name of the game, and Gunpower design their guns to be, as they term it, 'a changeable platform', able to accept add-ons and upgrades, as and when. Unlike the Storm model, which has a longer front tube incorporating baffles, the Stealth has a shorter tube, but is still designed to take Gunpower's own screw-on silencer. The silencer is sold as an optional extra, but shown here on test. Gunpower also sent me one of their branded 4-16x50 scopes and mounts for the duration, so I had everything needed to get started.

The Stealth's main structure is machined from aircraft-grade aluminium, perfectly complemented by the composite/polymer fore end and pistol grip. The sizeable 490cc buddy bottle doubles up as the cheek piece and the adjustable clamp at the rear forms the butt plate. There's direct feed to the Lothar Walther barrel via a sliding breech, two-stage trigger, an auto-safety catch, and even an accessory rail.

Of course, the big selling point with these rifles is their 'take-down' credentials, i.e. the way they are designed to break down quickly into two main parts then easily fit into a small case, and this works a treat. Just unscrew the entire rear bottle assembly from the huge connecting thread into the rear of the action, and you're almost there. Quickly, unscrew the silencer, and the Stealth is now ready to stow. The soft case supplied is fine, with Velcro securing straps, but it is a little flimsy, so I would be tempted to add some extra padding, just to keep everything super-snug.

Charging regimen

Gunpower recommend the buddy bottle be filled to a pressure of 3000 psi (approximately 200bar), and this is achieved by screwing the bottle into its adaptor, then screwing this assembly directly onto a diver's bottle. Reassembly of the Stealth is simple, courtesy of that chunky thread. Everything grips and tightens easily, with the butt automatically lining up, which is reassuring. One key observation at this stage is that the action remains inoperable until the bottle is reconnected; thus keeping everything nice and legal.

There is a utilitarian approach with this model, and undoubtedly, the sight line is a bit low, but the length of pull is adjustable via that bottle clamp, as is the butt plate, with three positions possible. In use, the rubbery feel to both the fore end and pistol grip works well, as does the padding applied to the buddy bottle- for comfort on a winter morning.

As for the rather basic-looking trigger, it is two-stage, but the mechanism is non-adjustable, other than the position of the finger shoe.

Down range

My test model was tweaked and adjusted to suit and it was time to head to the range.

Cocking the action requires very little effort; just pushing back the padded lever, and this cocks the hammer and exposes the breech. Now a pellet can be directly fed into the Lothar Walther barrel, and the lever pulled rearward and gently nudged left or right for retention. It has to be said that the locking point could be more positive, but I had no problems on test. The auto-safety is now set, requiring the tab just forward of the trigger to be pushed forward before the shot can be taken. This is a bit crude, but it does the job.

A small amount of creep in the trigger needs to be taken up, but the final release is perfectly acceptable. The Stealth emits what is best described as a 'satisfying snap' during the firing cycle, and with half-inch clusters over 30 yards, achieved with both Air Arms Diabolo Field, and Webley Mosquito ammo, I finished my afternoon session fairly satisfied, and reassured. Don't forget this system allows the shooter to feel the pellets connect with the rifling as they are chambered, thus detecting either too slack or too tight a fit, which is always conducive to good accuracy.

Shot count

Shot count with these rifles should be significant, given that 490cc buddy bottle on board, although the action is unregulated, so we can't expect too much. Recorded velocity figures replicated my findings with previous Gunpower models, with velocities dropping by around 70fps over the first 130 shots, from a fill pressure of 200bar, down to a residual pressure of 140bar. For the record, the first 50 shots showed a creditable 26fps total spread. Take the first 80 shots, and total spread was 46fps, so the conclusion for more serious shooting, is to take the top of the charge and those initial 50 shots.

Brand loyalty

In short, the Stealth is a gun that you want to pick up, and it certainly delivers impressive down-range accuracy, yet an honest appraisal has to conclude that in a competitive market, there are a handful of airguns that will probably offer more sophistication than is on offer here. Gunpower continues to thrive and appeal to a customer base that appreciate the portability, bombproof construction, no-nonsense approach, and yes, those Star Trek looks, and long may that continue.

Specification

Model: Stealth MKIII

Manufacturer: Gunpower, UK

Type: Take-down PCP

Calibre: .22 (.177, .20 & .25 avail)

Weight: 5.25lbs

Length: 29 inches

Barrel: Lothar Walther 12"

Stock: 3-part composite

Power source: 490cc buddy bottle

Trigger: 2-stage, adjustable for position

Fill pressure: 200bar

Shot count: 450-500 shots in .22 (tested over first 130 shots)

Velocity:

First 50 shots

First 80 shots

First 130 shots

High 575fps 575 575

Low 549 547 505

Ave 563 547 532

Spread 26fps 46fps 70fps

Energy:

11.3 ft.lbs.

10.6 ft.lbs.

10 ft.lbs.

Options: Silencer £55, Filling adaptor £35, Gunpower 4-16x50 scope £120, Mounts £22

Contact: Gunpower Ltd at gunpower.net / 01233 642357

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Read our review of the Gunpower Stealth