Designing since 1994 in the heart of England

RFD No 55/00000002542

A fully professional design and development service :-
* 3D Models.
* CNC Produced, Prototypes.
* Detailed production drawings.
* Assistance with manufacturing techniques and tooling.
* Ongoing Technical assistance and product development.

Graham said on the 20/10/2016 19:22:58

Reaper Development Trail

Air Capsule Bare Action

Back in 2003 when we were experiencing the first cases of bird flu here in the UK, I was asked if it was possible to produce a system type rifle for professional used to cull a wide range of birds in various places some of which might be public. This was always conceived as a piece of equipment that would have to be registered as a firearm and require a permit for use.

System Rifle:- the reason this was required was that it had to fulfil many roles because it could be required for culling different weights of bird, mainly from pigeon to swan or goose, at various ranges and in different situations such as at long range out on a moor or on water to close in, such as in city centres. It was suggested that it should be capable of folding up quite small and going into a fairly inconspicuous case for carrying through public places. However, this in its self, poses a legal problem as it must not be capable of being used as an over 6 ft/lb rated pistol which could be concealed for other reasons.

One of the problems with the bird flu virus H5N1 is that any blood that was spilled could be highly contagious and should be avoided at all costs. This caused me to consult with a world renowned specialist in the use of venom and its harvesting to see if there was anything we could do to over come this problem and it turned out that there were some options that would have worked humanely on animals of up to 10 kg in weight without being too dangerous to human beings but fortunately the luck of the gods were with us and the pandemic subsided, so it was not required. However, I had come up with a system that would fulfil all the requirements if it was ever needed in the future.

My solution was the system that I am now calling, the Air Capsule System and model name the Trim Reaper it works in the same way that an army field gun used to do. IE the bullet or projectile is loaded into the breach first and then the charge that is required to propel it is loaded behind because this gives the widest possible range of combinations of use. In this case the propellant is an air capsule that can be charged up to virtually any pressure from 500 to 4500 lbs/square inch or 30 to 300 bar in metric terms. The original rifle was designed to have a maximum power level of 60 ft/lbs or 75 joules. The projectile can range from a simple air gun pellet to a special hypodermic dart or for more power, a full form bullet can be used. I chose to use a 0.25 inch or 6.35 mm calibre barrel because it is more efficient power wise, than the smaller options.

The action is relatively straight forward to manufacture and consists of the barrel plus a simple bolt and trigger system that cannot be used without a suitable capsule being inserted into the breach behind the chosen projectile. This type of action is extremely power efficient due to the way that the air is released directly behind the bullet and the all up weight of the test rifle with stock, pistol grip, fore end, scope and mounts plus capsule in place ready to fire is exactly 6.5 lbs. The trap door in the bottom of the pistol grip holds the capsule service tools and seals.

The capsule is a self-propelled power source which has a very efficient inlet valve and manually controlled firing valve which can only be released by the trigger and ensures that all the air is directed behind the projectile without leaks, it can be pumped up from a diving bottle or a high pressure stirrup pump. A shooter can have as many capsules recharged and ready for use as He or She requires. The option of being able to use capsules charged as low as only 500 psi is very useful because the effort required to charge it, is lower and this provides good short range performance without the risk of over shooting or ricocheting. Low pressure can also be used to propel lightweight darts if required. It was also correspondingly quieter.
However, the capability of being able to charge capsules up to 4500 psi gives superb long range performance and changes it into a high-powered rifle. For intermediate uses any pressure in between can be pumped to suit the required task at hand. The capsule can be used and re-used many times and if necessary can be serviced with the kit of tools stored within the pistol grip. The test capsule has been used many times and so far has not required servicing. However constant use at the highest pressures will mean that seals will need to be changed from time to time but these are fairly normal "O" rings that are readily available on eBay or at most seal specialists.

By far the best way of charging the capsules is with the new high efficiency high performance pump adaptor system currently being developed in our work shops and will be on show here in the very near future.

It was noticed during testing that even on high power, that although this rifle makes a bang/crack it did not carry too far and was not heard 100 yards away over open ground.

When the bird flu threat subsided and having done a lot of development work on this project I realized that this rifle could also be used for other things such as fox control and now that at GET-Designs we have our own barrel making facility and much larger calibres can be made which makes this rifle a much more universal tool.

We have been doing development on an air shotgun and this system can be used very successfully with air shotgun cartridges our 14mm ones are very consistent at up to 40 yards. It is possible to make this rifle in different sizes with various capsule volumes and the largest will fire a 1 ounce slug (438 grains) or 28 grams at 1000 ft/sec (300 metres/sec) which is around 1000 ft/lbs.1250 joules.

Whilst suitable for the professional pest control use that it was originally designed for, I do not consider this form of weapon to be suitable for the general UK air gun market and therefore for greater appeal in the USA I have now married the action up with standard M15 type stock and pistol grip. I have used my own style of fore end out of preference but this could also be a standard one too.

The current version is extremely accurate and a thrill to use which should appeal to those self-supporting survivalists among us who do not want to be reliant on anything other than a pump, some lead and perhaps a few moulds. I envisage that who ever manufactures it for the open market, will make a cased version with action, a number of capsules, a pump, inter-changeable barrels and various projectile options.

To recap this is a single shot system rifle that can be dismantled for ease of transportation, it can be of almost any power level and have interchangeable barrels. This enables it to fire a wide range of projectiles including:- Bullets, Airgun pellets, Darts, Shot Shells and even Arrows plus it has no muzzle flash or noticeable recoil. We are working on multi shot versions for other uses and one of those can be seen at 3 Shot Air Capsule Rifle.

Whilst never intended as Sales Media at various times two videos were shot of this action one was in the early stages and just shows the capsule idea and how it can be simply charged from a diving bottle however the tools used were only development stage ones and do not constitute those which would be used today.


The second video, Reaper Prototype, was done more recently and my friend Mat who was taking the video, had not seen this rifle before and had no idea that I was going to get him to try it on camera, it was just a spur of the moment thought that I had as I was doing it. Please note that since the video I have changed the cap screw for a thumb screw as shown above to avoid the need for an Allen wrench when assembling.


It was interesting to note that the target board used to shoot at, in this video (a piece of new 19mm high Density Fibre Board) was the one that Mat had used the night before to zero his .22 Hornet rifle and the entrance hole of the Hornet was around 5 mm and its exit just over 8 mm. The entrance hole from the Reaper with its hexagonal hollow nose 32 grain bullets (H&N Grizzly) was 6mm and the corresponding exit was over 25 mm which is just the sort of thing that most hunters are looking for from a small game hunting rifle. This is probably why the impact noise on the board was so pronounced that it caused Mat to comment on it.

Whilst this weapon may not be legal for use in some countries especially in its pistol version there are a few more variations of it, shown below. This design is now up for sale and any manufacturer should get in touch ASAP via our contact page if they would like further details. This design that could very well suit a conventional rifle or shot gun manufacturer wishing to break into the fast growing air weapon market because GET Designs can supply all the technical information that will be needed.

Please click on the pictures below for more information about each one.


                          This is definitely one of those rifles that once you have fired it, it becomes a real "must have" item.

Reaper 300 ModelReaper PistolPistol with Stock Fitted

More in the series ...
From Humble Beginnings
Paradigm Development part 1
Paradigm Development part 2
Paradigm Development part 3
Whirlwind CNC Rifling Machine
Twin Opposing Piston Spring Rifles Preface
My First Ever PCP rifle
3D Printing And Air Weapon Development



Technical Computer Support by 1st Line Support