Andy McLachlan attempts to separate fact from myth when it comes to these small devices, said to improve your accuracy
Many outdoor airgun competition shooters like to use some form of ‘air stripping’ device. These come in the form of an add-on unit that is semi-permanently attached to the end of the barrel, with its primary function being to deflect the exhausting high-pressure air blast that is responsible for propelling the pellet to the target. The widely held belief is that if the escaping blast of turbulent air can be prevented from reaching the pellet as it exits the barrel, a much more accurately placed strike on target will result, due to the pellet’s less disturbed flight path – certainly as it exits the muzzle of the rifle.
Over the years, many inconclusive tests have been carried out regarding how effective the humble air stripper in its many designs and formats actually is. It is very often the case that little, if any actual evidence exists to support the case one way or the other. Many of these items allow the user to adjust the internal arrangement of baffles or deflectors to maximise the effect upon individual pellet weights or brands, which may have a positive effect upon overall shot placement group sizes, for example.
One of the products designed to further improve shot placement accuracy is the Steyr Double Cone Stripper. There are many hundreds of successful shooters using Steyr-branded products who do perfectly well without a DCS attached to the end of their barrel. So, what, if any, advantages does the inclusion of this innocuous-looking unit give us as we loose off an individual shot?
I asked several top competitors – not all using Steyrs, incidentally – why they used a DCS in preference to other available units. It transpired that the DCS was not necessarily used to further tighten group sizes, but that its inclusion further deadens the firing cycle of the gun and most importantly reduces any muzzle flip to negligible amounts. This is important because, unlike firearms, our projectiles tend to be still in the barrel as the effects of recoil manifest themselves, and are likely to affect shot placement. If this is constant, we learn to manage these forces and incorporate our management of them into our regular shot routine. I am not saying that we are having to manage a proper ‘bounce’ from a PCP barrel unless we are well into high FAC velocities, but a very minimal movement is present at the muzzle as the pellet exits from most PCP barrels.
We then move into the realm of barrel harmonics and vibration frequencies and ‘nodes’, which have a proven effect on accuracy. It could be that just adding minimal weight in the form of any air-stripper device will improve the ability of the barrel to move in a way best-suited to optimise accuracy.
The DCS contains two separate air-deflecting cones. These appear to have the effect of swiftly exhausting the destabilising air blast via the separate venting, and are presumably the reason for the lack of muzzle flip due to equalising jets of air exiting each of the vents. One thing is for sure: a manufacturer of high-quality target rifles such as Steyr is not going to waste its time or the considerable expense of developing aids to the accurate shooting of its products unless they have a positive outcome.
There are many excellent products available to those shooters wishing to consider the use of an air stripper. You will need to accurately measure the external diameter of your barrel prior to ordering – unless, of course, the manufacturer states which model of gun its product is designed for, as Rowan Engineering does, for instance. If the unit is adjustable, follow the manufacturer’s instructions before applying the Allen keys!