Airguns are fascinating tools and the issue of regulators is indeed a topic all on its own. We are obviously concerned with the pre-charged (PCP) action here, and it’s a subject which can divide opinion. So here we cover some basics; to hopefully make any purchasing decision that bit easier
Quick History Lesson
PCP’s are often assumed to be a modern invention, but they actually go right back to the Napoleonic Wars, where hugely powerful brass ‘ball reservoir’ guns were used in combat.
Fast forward to the 1970’s, and it is indeed Daystate that are recognized pioneers of the pneumatic for the modern era.
Their early Huntsman model was an instant hit, despite needing to be charged externally with either a divers bottle or pump, and the modern PCP had arrived.
Knock-open Valve
Those early models utilized what’s known as a knock-open valve, and the principle is straightforward enough. As the trigger is pulled, a small hammer strikes the valve and a pulse of air is released to power the pellet. However, over a number of shots, the pressure in the main cylinder inevitably drops, and this has the result that the valve can open more easily. The shot cycle from this type of airgun from a full charge, will typically see a number of shots at the start which are underpowered, then a run of shots which are fairly stable, then a tail off of in velocity over the latter shots, as the main cylinder pressure significantly drops.
This UNREGULATED ‘power curve’ varies wildly dependent upon the design of airgun, and some systems are simply more efficient than others. Some guns are specified as having a self-regulating valve, and meter air in a simple way but can be surprisingly effective.
Regulated Power
A dedicated regulator however, is a small device, which sits either inside the cylinder or at the end of the cylinder, and in this configuration, when the trigger is pulled, the hammer again opens the valve, but this time the regulator allows an exact volume of air to pass through each time, irrespective of the residual pressure in the main cylinder. Thus the power curve, is significantly straightened out and consistent velocity is the result.
The system can be more sophisticated with some manufacturers such as the highly innovative FX Airguns producing models with twin regulators. Often more relevant to FAC power levels, the idea here is that one regulator feeds into another, allowing valves to handle a lower pressure.
Which Do I Need?
There are no hard and fast rules, and this blog is intended as a guide only, but the basic principle is that, if the shooting planned is to be serious- such as hunting or competition work rather than informal plinking, range work, then a more consistent regulated airgun could make sense.
A key point with regulators is that they bring piece of mind, and they allow the shooter to be more casual as to what pressure their gun is filled to. Overcharge an unregulated gun, and you will probably have to fire off a few shots before velocity levels out, for the reasons above. However, overcharge or under-charge a regulated gun, and it should produce much the same velocity time after time, until residual main pressure drops below the regulator’s working pressure.
Regulated rifles normally offer more usable consistent shots, when comparing a regulated version against an unregulated version of the same model. However, with an unregulated model, the key can be to check a whole cylinder’s worth of shots over a chronograph. This will show what specific working pressure, produces the largest band of consistent shots.
The Air Arms S400 is a good example. Air Arms recommend 190bar fill pressure and this will produce the most shots, but a particular specimen, may well produce a super consistent band of shots when charged to 180bar or less.
Airguns can be quirky, and a particular action may just like a certain fill pressure; but with this homework undertaken, the S400 can be a highly competitive rifle. You’ll obviously get less shots at a lower pressure, but it may still produce 60 or so in a consistent band- plenty enough for many scenarios.
So the obvious question here is why regulate it? But care needs to be taken with that charge pressure, and that for some, is reason enough to take the regulator route.
Expected Shot Count
Conventional PCP design sees many guns configured with a straight cylinder underneath the barrel, and these will produce anything from 45-100 shots roughly, dependent upon the model. Buddy Bottle designs, where that large tank sits up front, can often produce a far greater shot count, more in the region of 200-600 shots – all dependent upon model and specification.
Many manufacturers now offer non regulated and regulated models to maximize shot count potential; and back to Daystate, the pioneers of the modern PCP, their electronically regulated guns continue to keep them at the forefront of design.
After-market
Precision regulators can also be purchased as after-market add-on accessories; normally for certain popular models, from companies such as Lanes, HUMA, and others, so it can be seen as an upgrade further down the line.
Conclusion
So in conclusion, many shooters put great store by paying a premium for a rifle fitted with a regulator. However, the down side is it introduces an extra layer of complexity – in basic terms, something else to go wrong. That said, with modern manufacturing standards and machining tolerances, many brands are very reliable and well made. As always, it comes down to the individual, their planned type of shooting, and personal requirements. One things for sure – today’s airgun market is an exciting place, with an ever expanding choice, covering all bases, so come and have a chat for more guidance.
Happy shooting
Range & Country
