What’s Best For My Airgun: A Booster Pump Or Portable Compressor?

HAM recently tested the airgun booster pump from Extreme Big Bore Air Rifles. Now comes the big question: “What’s best for my airgun: a booster pump or portable compressor?”

Before going further, I’d like to thank Bernard Fouché – a HAM reader from France. Bernard contacted me with some observations about our Extreme Booster Pump review. That was the inspiration behind this story. Thanks Bernard!!!

Background: Booster Pump Or Portable Compressor?

This is a question of growing importance for airgunners as the maximum fill pressure of PCPs increases. For example, the Umarex Gauntlet debuted just a few years ago with 3,000 PSI fill pressure capability. In 2021, the new Umarex Gauntlet 2 now fills to 4,500 PSI.

So it’s no longer just expensive big bore air rifles that need very high fill pressures!

Below. Filling a Benjamin Bulldog using a Booster Pump.

Booster Pump Or Portable Compressor?

It’s clear that airgun manufacturers are increasingly looking to higher fill pressures as a way to achieve increased performance for their PCP air rifles. A higher fill pressure allows either a higher power level or a larger number of shots per fill before the regulator set pressure is reached. Or both!

But it’s not always so easy to completely fill a PCP working with such a high fill pressure.

Sure, almost every “non big bore” PCP air rifle of any quality nowadays is fitted with a regulator. So it’s arguable that you don’t NEED to fill the gun to its maximum fill pressure. As long as there’s more pressure than the regulator delivers, the gun will shoot at full power.

True. However not for so many shots…

Accepting a lower fill pressure than your gun can handle likely means that you compromise on the number of consistent shots achieved before re-filling. But – of course – most of us want to realize the full performance potential of that shiny new PCP air rifle we just purchased!

Below, the RTI Prophet is typical of newer PCPs with it’s maximum fill pressure of 300 Bar (4,351 PSI).

So now that 4,500 PSI – or thereabouts – is becoming a common maximum fill pressure for PCP air rifles, it places a renewed emphasis on how best to fill them.

  • Hand pump? Don’t even think about it!
  • HPA tank? Yes, possible.
  • Compressor? Yup, that’s another choice.
  • Booster pump? If you have an existing HPA tank, definitely.

The issue we face here is that most HPA tanks have a maximum fill pressure of 4,500 PSI. That’s also the same pressure as most HPA compressors intended for airguns.

Below. The Umarex Ready Air is a new entry into the portable HPA compressor market.

Portable Compressor Benefits

Obviously a 4,500 PSI airgun compressor can fill your shiny new PCP to fill capacity every time. However it requires an electricity supply. Also portable HPA compressors – even fairly high-end ones – are relatively slow. Filling your PCP is going to take several minutes, or more, depending on the compressor and the PCP’s air capacity.

A slow fill and the requirement for electricity may be quite acceptable if you’re filling the gun at home and time is not an issue. But what about if you’re at the range or in the field?

There’s somewhat of a proliferation of relatively low cost, relatively portable airgun HPA compressors and most of them can be used with an inverter to run them from a DC supply. Like a car or truck battery, for example.

Booster Pump Or Portable Compressor?

Although I’ve never heard of a disaster of this nature, I’m always somewhat worried that powering a portable HPA compressor to a car battery could result in frying my vehicle’s electrical system. That would be a VERY expensive attempt to fill a PCP!

And sometimes you may not have a handy supply of mains electricity or be very near to a car or truck. If you need more air, what then?

Below. When talking about portable HPA compressors, we’re excluding bigger, higher capacity “static” compressors like this Daystate LC 110 model that’s available from Airguns of Arizona.

Booster Pump Background

Most existing PCP users already own a 4,500 PSI capacity HPA tank. But – even if your tank is filled to 4,500 PSI, you’re not going to achieve a completely full 4,500 PSI fill of your air rifle. And subsequent fills will inevitably produce lower pressures in the gun as the pressure of HPA in the tank drains with each use.

The HAM Team was impressed with the way the Extreme Booster Pump worked and its ability to “magically” fill an air rifle to a higher pressure than the HPA tank it’s connected to. If your new air rifle requires filling to 4,500 PSI, this is a way to consistently achieve that from your existing HPA tank, even if it contains a much lower pressure.

Moreover, the booster pump requires no source of electrical power. It operates entirely from air pressure.

And it works rapidly, too. You’ll likely re-fill your PCP in well under a minute.


Moisture – The Hidden Enemy Of PCPs

So, what’s better, a booster pump or portable compressor? The answer will be different for each user. However there’s one other aspect to consider…

It’s known that moisture in High Pressure Air can cause serious damage to any PCP air rifle. Logically, it’s likely that the corrosion resulting in the gun will become more extreme, more rapidly, with higher fill pressures. Like this…

This means that filling your 4,500 PSI air rifle with DRY HPA becomes a very important requirement. If you have your HPA tank filled at a dive shop, or you have a home compressor with a high quality desiccant system, that’s good. It also means that the HPA used to fill your air rifle will also be as dry as possible if you use a booster pump.

Below. This Omega CleanAir Inline filter from Airguns of Arizona has good desiccant capabilities.

If you use a small portable compressor, you’re going to need (and carry around) an effective and suitable desiccant system to use every time you refill the gun. Hmmm…..

Conclusions – Booster Pump Or Portable Compressor?

So, what’s better, a booster pump or portable compressor? As we’ve seen, there’s no one universal answer to this question.

If your air rifle requires a 4,500 PSI fill and you already have a large HPA tank that’s filled with dry air, then a booster pump probably makes a ton of sense.

It’s also much quicker to fill a PCP with a booster pump than using a portable compressor, which may be a big consideration for some. And if there’s no power supply around, there’s no other real choice.

And many in the U.S. will patriotically prefer to buy a product like the Extreme Booster Pump that’s made in the USA. But it’s likely to be more expensive than a portable compressor…

Booster Pump Or Portable Compressor?

If you need a full 4,500 PSI – or thereabouts – fill every time and don’t have a HPA tank, then a compressor is likely to be the best route. So long as you have an efficient desiccant system to work with it and access to electrical power, that is.

Here’s a summary of points to consider when answering the question: “What’s best for my airgun: a booster pump or portable compressor?”

 Portable CompressorBooster Pump
Speed of operationRelatively slow (some minutes per top-up)Fast (well under a minute per top-up)
Works with HPA tankMost do notYes (better with a large tank)
Needs electrical powerYesNo
Needs desiccant filterYesMay not if tank is filled with dry air
PriceMany choices but likely to be lowerLikely to be more expensive
Country of manufactureChinaUSA- Extreme Booster Pump