SMK’s CO2 powered rifles - the QB78 Deluxe, XS78 and XS79
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- Last updated: 03/08/2017
My test models here are three of their ‘Supergrade’ rifles all based around the same robust action. They all utilize carbon dioxide gas (CO2) as the power source, which should mean maximum fun for minimum input. It should also be pointed out that something of a cult following exists for these rifles, largely the result of that simple yet streamlined action, affording the QB78 and XS78 models at least, the appearance and uncluttered lines of a cartridge ammo stalking rifle. With a burgeoning after-market in spares, specialist modifications and tune-ups, all dedicated to these CO2 favourites, their future is assured. So let’s take a closer look and see what all the fuss is about.
CO2 as a power source can be a little unstable, so velocity and energy can vary depending upon ambient temperature. Given that all three rifles on test are beginners models, their modest power output and any slight fluctuations, will probably go un-noticed, so as such, is largely irrelevant. Despite their asking prices - placing these models strictly in the budget category - they have a solid feel and a level of finish which is bound to impress. So let’s look at the first one.
The XS79 model takes the large bulk fill 88gramme CO2 cylinder, which, once screwed into place, is good for 180-200 shots. Of course the cost of these disposable cylinders needs to be factored in (at around £6.99 a throw), but they do allow fairly prolonged shooting sessions to take place before a refill is needed. The downside of this design is that, because the forend is curtailed, the CO2 cylinder itself becomes the forend, meaning the leading hand has to grip a cold cylinder instead of the comfort of woodwork.
The hardwood beech stock fitted to this model exhibits some very attractive grain pattern, whilst the thick lacquered finish and rubber butt pad all add to the overall impression.
Conventional iron/open sights come fitted to this XS79, although they are rather basic and awkward to adjust. Most owners, I suspect, will be fitting glassware of some sort fairly early on, and this is made easy by the provision of extended scope rails, which run the full length of the breech block.
Removing and replacing the 88gramme CO2 capsule is made easy and safer by the addition of a knurled adapter collar, which allows any unused gas to escape safely via the vent hole.
The XS78 and QB78 Deluxe
Both these models follow the same layout, and require two 12gramme CO2 ‘bulbs’ to be inserted back to back inside the cylinder. Once the knurled end cap, just forward of the forend, is screwed into place, the bulbs are pierced and CO2 is released as required. This arrangement provides around 40 shots before the power drops, and with the 12gramme bulbs costing around 75p each, again, the extra cost of shooting needs to be borne in mind.
CO2 basically offers its own contained power unit, so the action can be free from springs and pistons, purely requiring a simple internal valve to meter the CO2. This allows for much lighter designs, and with these models tipping the scales between 5.28 and 5.75lbs, any newcomer should find them wholly manageable.
The QB78 Deluxe model offers a gold anodised bolt handle and trigger blade, which adds a touch of class to an already attractive rifle. Add in a properly adjustable set of fibre optic open sights, and the extra £20 suddenly seems a bargain.
Bolt and Trigger
All three rifles incorporate the same barrel over cylinder arrangement, and all three include a bolt mechanism, which is very easy to pull back, then slightly irritating to push forward and lock down. I have been reliably informed that this should improve with use, but the bolt is definitely over-sprung and a little stiff, which just takes the edge off an otherwise enjoyable experience. As for that plastic barrel support (fitted to all three models), this could be removed by the more adventurous owner, restoring true floating barrel status at a stroke.
I believe all these niggles are the subject of the XS78/XS79 Appreciation Society (I kid you not), so someone out there will be tuning, modifying and re-jigging these idiosyncrasies as we speak. The bolt and single stage trigger would be a good place to start, yet consider those RRP’s again, and the slightly creepy trigger is both perfectly usable, and even attractive, given its curved shape within a cast guard.
Being CO2 powered, all these rifles are recoilless, and with accuracy of around 3/4 inch at 20yds (achieved using the recommended .22 Milbro Select), close range hunting is also a possibility.
CO2? It’s a Gas…
Ok; I’ll admit, I’m normally no great fan of CO2, yet legions of shooters are. All I can say is I certainly warmed to these models whilst they were in my care, representing as they do, some of the best examples out there.
PRICES: £129.95 / £109.95 / £109.95