by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1
Part 2

Octane combo
Umarex Octane gas-spring rifle combo.

Today is the start of accuracy testing for the Octane combo air rifle, and I’m going to make some changes. For starters, I’m going to give you the summary now. The Octane is a smooth-shooting, accurate air rifle. It’s everything the manufacturer wants it to be, and a couple of things they probably didn’t think about, on top of that. The rest of this report will justify and explain my summary.

Another thing, the Octane is different from any gas spring I’ve ever tested. Gas springs always fire fast, as in instantaneously. When the sear releases, the shot is over, and you usually know it from the sharp crack of sound and the painful slap to your cheek. The Octane fires slowly in comparison. There’s a lot of forward recoil and almost no vibration, and the discharge is very quiet, as I noted in part 2. I attribute this behavior to the Reaxis gas-spring design that’s reversed from the norm, and to the SilencAir silencer on the muzzle. Both apparently work as advertised.

The test
I decided to just shoot 5 shots per pellet today, and to shoot the rifle with open sights at 10 meters. I wanted to get a good sense of how accurate it is before putting the walls of my house at risk. And what I discovered was that this rifle is fun to shoot! I normally don’t have much fun shooting a 20 foot-pound spring rifle, but the Octane is so civilized that it gave me a lot of confidence. By the time I’d fired the first 2 shots at the target, putting them into the same hole, by the way, I knew this day was going to be fun.

I held the rifle with an artillery hold, but the thumbhole stock makes you grip the gun harder than you normally might. So, I would have to call it a modified artillery hold. But the rifle cooperated, and there was noting to worry about. The muzzle heaviness holds the front sight steady on target once you’re dialed in.

The sights are fiberoptic, which destroy all attempts at precision, but by lighting the target brightly and sitting in a darker room to shoot, I could defeat the fiberoptic tubes and get a very sharp sight picture. When they don’t glow, the Octane’s sights offer a nearly ideal sight picture, and that was what made me decide to not mount the scope, yet. I wanted to have the fun of shooting with open sights since the rifle was cooperating.

The trigger is still quite heavy and very creepy, so I envy those who own their rifles and can modify them. If I could drop the release weight to under 4 lbs. and if there was a way to eliminate all the second-stage creep, this trigger would help accuracy greatly.

Beeman Kodiaks
The first target was shot with 5 Beeman Kodiak pellets. This was when I first noticed how slow the Octane’s gas piston is. It feels like an airgun equivalent of a 45-70 single-shot. You feel the recoil and the rifle bounces around, but you know the pellet got out of the muzzle before all that started and that accuracy wasn’t affected in the slightest.

As I said, the first 2 pellets cut the same hole, though each made a distinctive mark. Then I stopped watching through the spotting scope and just shot the next 3 pellets. In the end, the group is larger than I would have liked for 10 meters, at 0.581 inches, but this is with open sights. Still, it is just 5 shots instead of 10.

Octane combo 10-metr Kodiak target
Five Beeman Kodiaks at 10 meters with open sights measure 0.581 inches between centers. It’s a good start!

RWS Hobby
Next, I tried the RWS Hobby pellet. It felt good while loading because it fit the breech tight but not overly so. And, though the point of impact shifted up a bit, the Hobby was quite accurate — putting 5 pellets into 0.368 inches! I thought that was remarkable. I couldn’t wait to test some more pellets!

Octane combo 10-meter RWS Hobby target
Five RWS Hobbys at 10 meters with open sights measure 0.368 inches between centers. Now, the rifle was giving me confidence.

RWS Superdome
Next, I tried the RWS Superdome. Here’s where you’re going to see something significant. RWS makes both Hobbys and Superdomes in Germany, and presumably they use the same lead alloy for both. And domed pellets are generally regarded to be the most accurate. Yet look at how the Superdomes did! They grouped horizontally, to exactly 1 inch, while the Hobbys stayed together.

You might try to blame me for getting tired at this point in the test, but there’s group coming that will show that I was still shooting my best. That’s one benefit of these 5 shot groups. They don’t tire me as quickly.

Octane combo 10-meter RWS Superdome target
Five RWS Superdomes at 10 meters measure a long 1 inch between centers. When you compare this group to the one made by the Hobbys, you see that Superdomes are not suited for this Octane.

Predators
Now, for those of you who think I might have slipped up on the last group, I shot 5 Predator Polymag pellets next. They’re a recognized premium pellet, just like the Superdomes, and I’ve shown some great groups using them in recent tests. But not this time. Instead of the group stringing sideways, the Predator group were stringing vertically. Five went into 0.982 inches, so we won’t be seeing them in any future tests of the Octane.

Octane combo 10-meter Predator target
Five Predator Polymag pellets made this vertical 0.982-inch group.

If you have now decided that I’ve gotten tired and ho-hum, what’s so special about the Octane if this is the best that it can do — hold on! I saved the best for last. Actually, the Octane saved the best for last because the next group is the last one I shot on this day.

Crosman Premier
The 14.3-grain Crosman Premier pellet is sometimes the best pellet you can use in an airgun. And it is in the Octane test! Five Premiers went into a group measuring 0.245 inches between centers. It looks like only 3 pellets have passed through, but I did shoot all 5. This is very clearly and hands-down the most accurate pellet I tested in the Octane.

Octane combo 10-meter Premier target
Five Crosman Premiers made this beautiful 0.245-inch group. It was the last group of the test. Who says the groups open up as you go? This is the pellet for this rifle.

Summary
I already gave you the summary in the beginning of this report. Now you see the substantiation of what was said.

Several readers reported higher velocities than I got in the last test, and I was asked to change the breech seal. Well, I might do that, but frankly the rifle is shooting so nice right now that I don’t feel any urgency.

The Octane is unlike any gas-spring breakbarrel rifle I’ve ever tested. I wish the trigger was better, but it’s hard to argue with the accuracy or with the rifle’s firing behavior.

I will skip testing the rifle at 10 meters with the scope that comes in the package and go straight to 25 yards next time.