Does The Umarex Komplete Shoot CO2? – Surprise!

Does the Umarex Komplete Shoot CO2? That’s one of the main questions I have been asked since Hard Air Magazine published our test review of this air rifle. So – of course – I had to check it out.

The short answer is “yes”. The Komplete actually works very well shooting CO2. It really is a “dual fuel” airgun. It works as both a PCP and a CO2-powered gun.

But there was a number of surprises involved in this test – for me at least – and we’ll cover them below…

First a reminder. In the Umarex Komplete we have a complete “PCP in a box”. There’s no need for a HPA tank, hand pump or compressor.

The power is provided by a screw-on, disposable NitroAir cartridge that’s pre-filled with 32 Grams of Nitrogen. It’s a revolutionary new take on the PCP air rifle concept.

In our HAM review, the Komplete earned a Gold Award. At less than $200, it is incredibly-well priced for a regulated, magazine-fed, sidelever action PCP with a shrouded barrel.

And now there’s more. It also works well on CO2!

BUY FROM PYRAMYD
Umarex Komplete NitroAir PCP Rifle 0.177

Does The Umarex Komplete Shoot CO2? – Surprise 1

The HAM test review of the Komplete was undertaken four months ago – in May 2024. As I had always intended to come back to this gun, I had left it with the Axeon scope mounted and the NitroAir cartridge in place.

In fact, the Nitro Air cartridge that I had used for the shootdown test was still in the Komplete.

Surprise one was that the Komplete had held pressure for four months! Of course it was not full pressure, but the Muzzle Velocity of a half dozen pellets fired downrange confirmed that there had been little or no pressure loss since I completed the previous test.

I was surprised and impressed by that!

Does The Umarex Komplete Shoot CO2? – Surprise 2

Given that the Komplete is designed to work on Nitrogen regulated to a pressure of 1,800 PSI, I wasn’t sure that it would work with CO2. After all, CO2 guns  typically work at somewhere between around 800 and 1,100 PSI, depending on temperature.

So my expectation was to be disappointed with the CO2 performance. I expected the hammer spring to be too strong to work well with the lower pressure gas.

My “Plan B” was to make a first attempt with CO2, but then to replace the hammer spring with that from the Umarex Fusion 2 – a dedicated CO2-powered gun.

Would the Fusion 2 hammer spring fit the Komplete? Dunno. However, both models are manufactured in the same factory, so there had to be hope. And I had a donor gun available and ready to hand.

Surprise two was that “Plan B” was unnecessary! The Komplete worked using the 88 Gram CO2 cartridge as its power source with no modifications at all.

Does The Umarex Komplete Shoot CO2? – Surprise 3

The next surprise was that I had forgotten how good the Komplete is to shoot!

With its combination of accuracy, pleasant trigger, easy sidelever cocking, compact size and light weight – not to mention the regulated action – this has to be by far the best-shooting air rifle at anywhere near its $200 selling price.

Of course that regulator is not used when shooting with CO2. But even so, I had forgotten what a great little gun the Komplete really is!

Does The Umarex Komplete Shoot CO2? – Surprise 4

Now to the main part of the test. How the gun shot.

Following instructions, I de-gassed the Komplete using the built-in degassing screw. Then I removed the NitroAir cartridge – then closed the degassing screw again before installing the Umarex 88 Gram CO2 cartridge. Most important, that!

By using the same gun, for this test I already had a baseline of performance with it working as a PCP on Nitrogen (N2). For consistency, I also decided to use pellets from the same tin. HAM Gold Award-winning H&N Field Target Trophy 8.64 Grain ammo was used for both tests.

As some of you will know, I have long experience with CO2-powered air rifles. So I was careful to “season” the gun and CO2 cartridge for several hours at the range temperature of 67 degrees Farenheit before starting the test.

Then – due to the cooling properties of CO2 – I fired the Komplete at a fairly steady rate, waiting 10 – 15 seconds between shots.

First, let’s remind ourselves of how the Komplete performed as intended. Here’s our test results firing the gun as a PCP with NitroAir power.

Here we see a very consistent shot string with 60 “good” shots before the gun comes off of the regulator.

Now let’s see the performance from the same gun, unchanged, with the same pellets using an 88 Gram cartridge of Umarex CO2.

Wow! Now we have 150 “good” shots from the one CO2 cartridge. True the Muzzle Velocity is less consistent than when using NitroAir. But it’s still pretty good, in my opinion.

Why the dip between shots 1 and 40? I have no idea!

Putting both graphs together at the same scale, we can see the comparison well.

Obviously the Komplete is much more powerful when fed it’s intended diet of Nitrogen. It’s also more consistent. But there’s a ton more shots available using CO2.

Another feature of CO2-powered airguns is that they shoot faster with increasing temperature. In fact I have found that the increase is around 2 FPS per change of one degree F temperature. PCPs have very small differences due to temperature changes.

Typically also, CO2-powered guns attain a condition called “valve lock” at a temperature of above 90 degrees F. At that point the Muzzle Velocity falls precipitously due to the increased pressure of the CO2 overcoming the strength of the hammer spring.

Given the design of the Komplete as PCP-powered air rifle, it’s possible that valve lock may not happen with this gun as it is designed to accept a higher gas working pressure. But I didn’t test this.

At any event, we can expect that the Komplete will shoot 46 FPS faster at 90 degrees F than in our 67 degree test range. We can now compare the results as follows.

Does The Umarex Komplete Shoot CO2? Summary Comparison

If we now calculate a few averages, we can see the N2 and CO2 results for our Komplete testing. As follows…

So that’s it! In answer to our question “Does the Umarex Komplete Shoot CO2?”, the answer is a definite “Yes”!

The Komplete is a real “dual fuel” air rifle. You could use it on CO2 for plinking and short-range targets, for example. While for hunting and longer-range work is well within its capabilities using the NitroAir N2 cartridges.

Either way, it’s a great little gun!

BUY FROM PYRAMYD
Umarex Komplete NitroAir PCP Rifle 0.177

The post Does The Umarex Komplete Shoot CO2? – Surprise! appeared first on Hard Air Magazine.