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SMK TH78D Thumbhole Deluxe CO2 sporter

SMK TH78D Thumbhole Deluxe CO2 sporter

Although CO2-powered airguns came ‘off ticket’ over a decade ago, it amazes me that the vast majority of guns that run this system are either pistols or fun-guns. A notable exception, however, is SMK’s new TH78D Sporter – a full-powered sporting rifle designed unashamedly for the hunting field.

Twin CO2 Capsules
CO2 format offers all the combined a
dvantages of spring guns and precharged pneumatics, but without any of their disadvantages. For instance, unlike a springer, you can keep a CO2 gun cocked for as long as you want, without having to worry about mainspring fatigue. A CO2 gun is pretty effortless to charge up, too. No cumbersome charging gear’s needed, nor manual stirrup-pumps to break your back as with a PCP. You just drop in a self-contained gas capsule… or, in the case of the TH78D, two!
You need two of the standard 12-gramme CO2 gas capsules because the TH78D’s returns upwards of 11ft/lbs of power at the muzzle. The capsules locate in the under-barrel chamber, and once you remove the cap and drop in the first capsule, neck-down, you follow up with a second, neck-up. Gassing up is easy; you hear a hiss that signifies the CO2’s released once you’ve tightened up the piercing cap.
Anyone who knows much about gas guns will be aware that this set up will give around four or five times more power than the single capsules produce out of pistols – yet, courtesy of its slow-release valve, SMK’s twin-capsule hunting rifle still returns around 50 shots per gas-up.

Down On The Farm

As with all CO2 guns, the actual power and shot output will vary dependent on the pellet type and ambient temperature, but I’ve not found the system to be a problem over the months that I’ve been using the TH78D for pest control work at my local farm.
I’d been ordered to thin-out the rats and feral pigeon. This type of vermin control calls for a fast-handling sporter, and I couldn’t think of a better gun for the task than the TH78D. It’s very light, beautifully balanced and its deluxe thumbhole stock makes it handle like a dream. In fact, having shot many hundreds of rounds through this rifle since I first began testing it months ago, I’d go so far as to say this is the kind of rifle you’d want if you were a professional pest controller!
It’s a fast-handling gun, too. Not just because of its manageable weight and beautiful balance, but also because of its delightful, ultra-quick bolt-action. Once lifted from its lock position, the bolt – which is gold-anodised to match the rifle’s trigger blade – is easy to pull back and has a very short throw.
Once the bolt’s fully drawn, the channel of the loading bay opens, allowing a pellet to be dropped in. This then gets ‘breached’, and the firing hammer cocked, once you return the bolt and lock it down.
The open sights, which feature a red fibre-optic foresight and a fully-adjustable rearsight with green fibre-optic inserts, are pretty decent in my book – but in my opinion this gun warrants a scope, which requires you to remove the rearsight to make room. I opted for an SMK 3-9 x 40 Mil-Dot which proved how the totally recoilless firing cycle of the CO2 system really makes the TH78D perform with pin-point precision.
Although most of my farmyard ratting work never required a shot more than 20 or so yards away, I took a woodpigeon at 33 paces with the TH78D. It flew into a grain store opposite the hay barn I was in and, taking full advantage of the mil-dot reticle, I was easily able to drop the bird from distance with a perfectly executed head shot.
Its rifled steel barrel means you can group your shots very tightly even at extreme ranges and the TH78D’s three-way adjustable, single-stage trigger is perfect for getting the best from both rifle and shooter.
The safety catch, at the front of the trigger guard, is manual and perfect for hunters. You point it forward to fire, back to engage it, and an arrow points to either ‘F’ and ‘S’ to let you know its status.

story continues below...

Put In a Thumb

I loved the rifle’s thumbhole stock – the reason for the model’s ‘TH’ suffix. Its grip is beautifully sculpted to fit into your palm, and its right-hand Monte Carlo cheek-piece is ideal when you rig up a scope.
Besides its perfect sporter shape, it’s also beautifully presented, with my test rifle showing a rich ‘red’ finish that highlighted the underlying grain a treat. Thanks to its height-adjustable butt pad, it’s practical, too.
The pad is nicely ridged and curved to nestle naturally into your shoulder, it moves up or down to give the best gun fit. I found that by not over-tightening the keeper screw, I could alter it ‘on the fly’ with the rifle in my shoulder. This helped when shooting at an upward angle – I simply slid the pad up to its top position, which dropped the butt and brought the gun on line with the target.

A Good Deal

With CO2 capsules costing just around 75 pence each and the rifle on sale in gun shops for only £179.95, I reckon SMK’s new TH78D must be one of the deals of the decade. I said earlier it’s a rifle that would suit professional pest controllers down to the ground – but it’s also such a beautifully finished gun that I’d want it in my gun cabinet for pride of ownership alone!

This test report has been adapted from an article that appears in Sportsmarketing’s new, 164-page Catalogue, which is available on request.

PRICE: £179.95

  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

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  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

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  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

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  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

    click on image to enlarge

  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

    click on image to enlarge

  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

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  • SMK TH78D Thumbhole Deluxe CO2 sporter - image {image:count}

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  • Model: Sportsmarketing TH78D
  • Action: Bolt-action CO2
  • Power source: 2 x 12g CO2 capsules
  • Calibre: .22
  • Length: 100.5cm
  • Barrel Length: 54cm
  • Weight: 2.4g
  • Trigger: Single-stage, three-way adjustable
  • Safety: Manual, resettable
  • Stock: Thumbhole beech
  • Sights: Adjustable fibre-optic open sights, plus dovetails for scope mounting
  • Power: 11+ ft/lbs


  • Hi,much of what is said here is probably true,but these rifles are received far from high power(11+ft lbs)I bought a QB78D when they were relatively new on the market and from the box it produced 7-7.5ftlbs at best! I also bought a custom upgrade kit(bolt,seals and valve assembly etc)as some components are a little short of high quality,it is probably best purchased as a rifle for modifying in my opinion,also co2 can be very temperamental as far as temperature is concerned,too cold and the pellet will more or less just drop out the end of the barrel! Too high and they are at risk of lock up.....I agree though the stock on this and the QB deluxe are well finished and do look very nice, personally I squeezed my action into an ags pcr1 stock,fitted a bsa silencer,adjustable butt pad,upgraded and modified all internals and fitted a 3-9x50mildot illuminated scope.and it will shoot groups within 5cm with Prometheus paragon and go clean through 1.5mm stainless steel at 30-40yrds easy.....

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    Andrew white
    06 Sep 2016 at 10:36 PM
  • To start with, it appears that the last comment was dated 02-02-2013, so I have no doubt that the magazine conversion kit listed in E-Bay has come to your notice by now. If not I enclose contact details now. The unit comes in two sizes, .22" (5 shots) & .177" (7 shot capacity) They both cost £28.00 with a further £8.00 postage, they come originally from Poland and from the photos, are hand made with rather a rough, Matt Black finish. However, having said all this, I intend to send for this kit in .177" for my TH78D which I have just ordered from my local gun shop. If all goes well, I shall also send for the bolt conversion kit + new springs washers etc, as well, so that I can bring my new gun up to max legal limit. I will post another comment as soon as I have completed this conversion and let you know if it is successful.

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    Mike B
    06 Mar 2016 at 03:28 PM
  • can you turn the th78d in to a multi shot. thanks

    Default profile image
    02 Feb 2013 at 07:48 PM
  • Best and simplest way for a bang on 12ft lb gun.

    1. Buy the Terry Robb tuning kit. .
    2. Buy a 'combro' chrono.
    3. Strip the gun (follow the Terry Robb CD) and clean properly, the gun is full of swarf and a piece of this will cause the valve to malfunction.
    4. Fit the tuning kit. If you fit the stronger hammer spring and the weaker valve spring you will be running it about 14ft lbs and could be in big trouble. That is why you must chrono the gun with the lightest pellets. If the gun is over start by cutting a coil or two off the hammer spring or fit a weaker one.
    5. Do not under estimate the consequences of possessing an air rifle over 12ft lbs without an FAC. You may not be allowed to to own an airgun again.

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    pete john
    01 Jul 2012 at 05:40 PM
  • Hello All,
    Im making a return to the sport after some 15 years break, things really have moved on, I live by the rule of you get what you pay for, the TH78d is very tempting and i've read in some forums that troubleshooting (no pun intended) and after sales service is pretty poor from SMK, does someone want to correct me there?
    I grew up on BSA's and Webley's (back to the get what you pay for thing),
    Now im not adverse to shelling (sorry again) out hard earned cash on a well established and proven brand but someone please be honest, just how good is the TH78d? and is it suitable for ratting / rabbiting?
    Thanks in advance

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    Funky Gibbon
    16 Jul 2011 at 11:59 PM
  • I believe that SMK can supply a silencer for the 78 - contact your local SMK dealer or take a look at their website at http://www.sportsmk.co.uk

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    Pat Farey
    22 Jun 2011 at 02:02 AM
  • can put a silencer on a th78d what make

    Default profile image
    22 Jun 2011 at 12:33 AM
  • I've just got my hands on a TH78D and was just woundering if you can attach a silencer to it, some sites say the one for the xs79 then other sites say NO. could some one help. thanks

    Default profile image
    23 Nov 2010 at 10:28 AM
  • Jordan,
    1.Have you properly zeroed your scope? (Normally done at 25 Yards).
    2.Use quality pellets.
    3.Is the gas low? (This is a un-regulated gun and will drop further and
    further as the gas goes. (After 30 or so shots even a novice will see the
    fall off in performance 2 cylinders only good for 50 or so shots).
    4. Are you shooting too far?
    If the above does not help, can you return the gun to the seller to check it out?
    Ask a fellow shooter to try the gun or even borrow a different scope.
    Hope the above helps, (we are all here to help you).
    Regards.. David.
    p.s. these are super guns and can be fixed.!!!

    Default profile image
    13 Sep 2010 at 08:44 PM
  • i have got a th78d and rite out of the box it was shooting low and i tryed a high scope mount but it didnt help and my scope wont go any higher can any one help me get over this problem

    Default profile image
    09 Sep 2010 at 02:35 AM
  • To find the muzzle energy of your rifle, take it to a gunshop or shooting club that has a chronometer and get them to test it for you with the pellets that you regularly use. This will give you the muzzle velocity and average muzzle energy of your rifle. However, please read the notes below.

    The legal limit for an air rifle in the UK is 12ft/lbs of energy at the muzzle, however most air rifles that claim to be 'legal limit full power' are in fact set by the manufacturer at between 11 and 11.5ft/lbs to keep them safely within the law.

    The reason for this is that just by using a different pellet to the one that the manufacturer used to test the rifle, you could raise or lower the muzzle energy. Also, your rifle uses CO2 as a propellant and a change in the outside air temperature could also affect the muzzle velocity. Other factors can also raise or lower the muzzle energy.

    The actual difference between 11ft/lbs and 12ft/lbs of energy is that you will have a slightly more curved trajectory. At sensible distances the pellet will still kill a rabbit if you aim correctly, it will still knock a field target over and it will still make a hole in paper.

    On the other hand, the reality of having an air rifle over the legal 12ft/lbs limit (even if unintentional) is that if you get caught and the police prosecute, you will be charged with possessing a firearm which could get you a 5 year 'compulsary' jail sentence.

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    pat farey
    05 Aug 2010 at 10:29 PM
  • Sirs having just purchased a th78 package from my local retailer I was informed that it was powered to maximum U.K allowance (approx 12'/lbs).
    Reading the above this now appears unlikely. How do/can i check it ?

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    stuart over
    05 Aug 2010 at 11:50 AM
  • For the comments above:
    This is a single shot, although an 8 or 10 shot magazine can be bought after-market. CO2 guns cannot be fired too rapidly though as the change in temperature (the compressed gas moving decreases the temperature) alters the power, 15 seconds between shots is more than enough.

    Mine was 8.5 lb/ft out of the box and was A LOT of fun to play with in the garden, but they CAN EASILY be tuned up to a reasonable, and legal limit, which would be more appropriate for hunting. I would not hunt anything larger than rats with one of these rifles straight out of the box, the idea is to kill, not to maim.

    Buy one, you wont be disappointed - then join http://ukchineseairgunforum.myfreeforum.org/index.php where they will show you how to tune, maintain and improve your gun whilst also staying legal.

    That's what I did, and I now have a great hunting rifle that I know inside out. Find me on the above forum under the nickname 'badger' (I'm just a member, I don't have any other vested interest) and let me know how you're getting on. 😊

    Default profile image
    03 Aug 2010 at 03:08 PM
  • The short answer is that you can't increase the power - well not in the UK. This is not so much a technical restriction as a legal one.

    The rifle is rated at around 11ft/lbs, which is safely below the UK 12ft/lbs legal limit but still powerful enough for most uses expected of an air rifle.

    The Airgun Manufacturers Trade Association (AMTA) recommend that you do not try to alter the power on any air rifle by yourself, as this may put the power over 12ft/lbs and make it illegal. For this reason many manufacturers give warnings against DIY 'tuning' and some even fit anti-tamper devices.

    If your rifle is operating at far less than 11ft/lbs you should approach the supplier - or the manufacturer/distributor - and ask them to increase the power.

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    pat farey
    28 Jul 2010 at 12:27 PM
  • i have a smk th78d i would like to know how do you increase the power

    Default profile image
    27 Jul 2010 at 08:31 PM
  • This is a single shot bolt action rifle and can't be converted.

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    Pat Farey
    24 Jul 2010 at 01:47 AM
  • can anyone tell me if this is a single shot or multi shot please, and if its a single shot can it be converted? thnx

    Default profile image
    23 Jul 2010 at 08:24 PM
  • The safety catch has to be put in the 'safe' position and 'punched' out with a wooden dowel to allow removal of the stock.

    I doubt if there has been a single TH/XS/QB78 to come into the UK that is running at 11ft/lb or more. More like 7-9ft/lb! But they are easily tunable to full power with the right knowledge ;0)

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    Mark Aldridge
    08 Jul 2010 at 10:18 PM
  • There must be a way of removing the safety or manuevering the stock around it. If in doubt refer to the instruction manual or consult the distributor, Sportsmarketing (SMK) on 01206 795333 http://www.sportsmk.co.uk

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    Pat Farey
    22 Jun 2010 at 04:15 PM
  • I have this rifle but can not see how to adjust triger as U can not remove stock as safety catch stops it

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    Chad Lobb
    22 Jun 2010 at 01:19 PM
  • i have one of these, and it has one hole. my old xs78 had one also. the purpose being to allow air to escape quicker when depressurising. i cannot see this being a safety issue or a point of worry a it just means you will have to depressurise more via the cocking bolt. just to add ( the hole on my xs78 was much larger than the th78 i have now. just have a close look as at 1st i didnt think it had one untill i had a really close look

    Default profile image
    29 May 2010 at 12:54 AM
  • I recently purchased two of these rifles. One had no vent hole in the resevoir tube threadsat all (see page 4 of Instruction Manual) the other had two - one at each end of the threads. Neither the retailer or the supplier have so far given me a definitive answer as to which - if any - is correct. Does anyone know how many and where the vent holes should be - if any? Is this a safety issue?

    Default profile image
    24 May 2010 at 11:32 AM