Octane combo from Umarex: Part 3

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.

59 thoughts on “Octane combo from Umarex: Part 3

  1. FYI for anybody interested in the Octane. Almost all of the creep and a substantial amount of pull weight can be eliminated by smoothing out the sharp point on the “first stage adjustment screw” located on the trigger. Without doing this it doesn’t smooth out it gets worse. If the gun has a fair amount of rounds through it you will also need to grind and polish the contact point where this screw hits on the “bottom sear”. Mine grouped similar with the Premieres and I was thrilled. Then I tried the JSBs that I ordered with it and was blown away, 1″ 12 shot groups(groups not group!) at 60 yards with a 5mph 4 o’clock wind. The rifle shoots better than I do. Also if you like to shoot the Gamo squirrel field targets, buy a couple extra because the Octane wrecks them after a good amount of shots. It’s winter now and I’ve moved indoors so I removed the scope and painted over the fiber optics with flat black paint. This works good enough to keep me busy until I can get an aperture sight fitted on it.



      • Sorry for not replying back sooner. I’m currently dealing with some debilitating medical issues. I have a .177 Octane and I shoot JSB heavys. Also for anybody interested in an Octane, it took well over 1000 shot cycles before it got really accurate. I believe due to mild diesling. I also just got a tin of JSB monsters and they group just as well at twenty yards).


    • I’m finding this rifle much more interesting than I’d have thought originally. It sounds like with a good trigger it would be a serious contender for the role of the 20 ft-lb breakbarrel. Thanks for the intel here!


    • Ben,
      I came to the exact same conclusion (about the adjustment screw)when going through the trigger on my octane as well. Fortunately it is the easiest part to get to in the trigger group. I’m surprised B.B.’s has so much creep in the “second” stage. Mine was very short and crisp out of the box, and I have heard the same from a couple other Octane owners. An easy fix would be to drill out the trigger pin hole that allows maximum sear contact to the next bit-sized hole and use an appropriate-sized pin. This will keep the sear from coming as far forward over the piston catch and reduce creep. With all the power the octane has, I wouldn’t change too much though. A bear trap from this thing would be terrifying. With moly, a lot of polishing and shimming, and a very mild geometry change to the sear I got my pull to a measured 3.5 lbs. It was actually a touch lighter right after the trigger job, but it has settled in to the current weight. The secret was to maintain the sear’s positive engagement, but reduce the angle of engagement by a fraction. I had to make a jig to get it just right and I reassembled and tested many, many times to get it to where I felt comfortable with the pull weight and the safety of the engagement. I have hammered on it with a rubber mallet and banged the buttstock on the ground and it is holding steady. It was not very easy to get the results though, because of the sloppy parts fit and the serious pressure of the reaxis piston on the components. I would recommend that most just polish the parts (especially the screw tip). It will do enough to get the pull down to 6 lbs or so. Mine was almost 10 out of the box.

      B.B.,
      I ran a Benjamin pellet sampler through my octane today. My previous best pellet has been the CPHP’s that shot so well from your Octane. I have been getting 3/8″ 10-shot groups at 25 yards with them. Well, the last pellet I tried today as the light was fading was the Beeman domed hollow point. I only shot one 10-shot group at 20 yards, but it measured 10mm from outside edges. My buddy just picked up a trail NP and was shooting the target next to mine. He watched in unfold and stopped shooting half way through the group. 10mm-5.5mm= a 4.5 mm group. The holes were a tad raggedy, so even if I were to call it 5mm, that’s still about a .2″ group. I have maybe seen one or two groups from my nitro piston CFR get close to this, but that’s out of hundreds of groups. To see that in my first test of this pellet blew my mind. It may have been a freak occurrence, but I will certainly find out tomorrow.

      What is so confusing to me is that the average weight from 10 of these pellets is 14.36 grains, which is right where the crosman premiers are, and being Benjamin pellets I thought they were just crosman premier hollow points. They look, weigh, and measure exactly the same, so is there a difference or did I just get a very lucky group? I’m almost afraid to find the answer when I go to 50 yards tomorrow.

      Anyway, thanks for testing this rifle for us. I knew from the first shot from my octane that it was a special rifle, and I’m glad to hear you are finding the same results. Now if they would just lighten up that trigger!


      • Oops. I meant to say “Benjamin hp” in the first instance, not “Beeman”, to clear things up. Beeman pellets are for tomorrow’s testing.



        • I would be glad to do a write-up on the trigger work. I’m in the middle of my finals right now, so it would be a little while before I could take that on, but once I finish the last of them I can give it a go. There is a good trigger job video already that was done by the founder of the Yahoo Octane Group, Tim Montano. It covers the trigger function and how the parts interact, as well as the areas he focused on for the improvements. I did a little extra by shimming the parts and polishing every contact surface, not just the catch for the piston. I can get into the change in sear geometry, but I must say that it would be quite easy to go too far and have a very dangerous rifle. The last thing I would want to do is teach someone how to make a bear trap.

          Here is a link to the video: http://www.youtube.com/watch?v=s3ttSkTLRDA

          And the Octane group: http://groups.yahoo.com/neo/groups/umarexoctane/info

          Both links are filled with good information. So, when I can get some pics taken and go through the steps of the trigger work, how should I get it to you?


  2. If you look at the Kodiaks, the Hobby’s and the Predators.They all make a vertical pattern. And the Superdomes a horizontal pattern.

    But look at what pellets grouped the best at the distance your shooting. The shorter pellets.

    And I like what you said about how the gun reacts when you take a shot.

    But I have to say something about the Superdomes. I have shot them through a bunch of different guns and you are probably going to think I’m crazy after I say this.

    But when I see a horizontal pattern it tells me the gun needs to be held tighter. Try it in your office when you get a chance with the Superdomes. Tell me what happens. I’m not going to say its going to be your best group. But I’m pretty sure it will tighten up. (maybe this nitro spring gun may need a different hold) That’s what I have seen with the Superdomes when I have shot them through different guns anyway. Even my PCP guns.

    Then another thing to bring up. Does that mean that the Crosman Premiers are more forgiving when you shoot them?


    • I should say the .177 Superdomes I have had good luck with.

      I tryed .22 cal. Superdomes and the .25 cal. also and they were not good at all in the guns I was shooting.
      And yes I tryed different holds with no luck. That’s what I experienced anyway.

      And when I said even my PCP guns. I meant I held the PCP gun tighter also.


      • Dude, you’re rambling. Go to bed.

        Usually the shorter pellets do indeed do better because the longer pellets are the generally the heavier ones and they add even more weight by thickening the skirt. That throws the center of gravity more toward the rear, making it less stable as it slows down.

        This is one of the reasons I usually start with JSBs and CPLs to see how an air gun performs.


        • Ha ha but why are the Superdome groups horizontal instead of vertical like the other longer pellets.

          And I kind of lean more to the JSB’s also.

          But what I was trying to say without painting a picture is. Maybe with the gas ram positioned this way the gun will require a different hold.

          Time Will Tell



            • I was sitting there in my robe with my first cup.

              As to the horizontal spread, you may be on to something. I had a CFX that would regularly produce 10 shot groups at 25 yards that could hide under a dime. With an almost imperceptible difference in pressure of my trigger hand thumb, I could move that group almost two inches to the side. It was very frustrating until I figured that out. That is why I am most hesitant to mess with sproingers and definitely will not even consider hunting with one.


              • With you on the springer’s for hunting. But I do like a springer to target practice with. Keeps me in practice on my holds.

                Quite a while back I got the Benjamin .25 cal. nitro spring gun that me and some of the people at work were supposed to do a little friendly competition together with.

                (Oh and by the way BB that fell through everybody that wanted to made up excuses and nothing happened)

                But what I was going to say is I tryed about (with out going out there and seeing) 7 different pellets in the gun and it is very hold sensitive. I was almost going to get rid of the gun because it was hard to control. But I kept it. And now when I get bored shooting my PCP guns I pull it out for a little challenge.


                • What pellet did you Benji .25 take a liking to? My friends settled down after 1000 rounds to liking Predators and Barracudas. Also, what sort of groups can you manage at 20 yards. I have a difficult time with that gun.


                  • Pop’s
                    On average the gun is grouping a bit over 1 inch at 25 yards. With .900″ being the best I shot with the gun.

                    At 50 yards I can only do a best of 2 inches. And the average group at 50 yards is about 2.800″.

                    Oh and that was 6 shot groups at 25 and 50 yards and of course bench resting the gun. And the groups are not pretty and round. But the Benjamin 27.8 grn. domes were the best for me anyway if you call that good.


    • Thank you for the advice on the tighter hold when you see a vertical string. I’m new to airguns but well expierenced with fire arms and compound bows. If you can think of anything else that is specific to spring/piston airguns I would appreciate hearing about it.


      • Ben
        The vertical string sometimes needs to be held tighter. But I was talking about the Superdomes and the horizontal pattern it made above in BB’s target.

        RidgeRunner said it best I believe.
        “I had a CFX that would regularly produce 10 shot groups at 25 yards that could hide under a dime. With an almost imperceptible difference in pressure of my trigger hand thumb, I could move that group almost two inches to the side. It was very frustrating until I figured that out”

        And also so many guns act differently it is hard to say what hold the gun needs. The best I can say is the more you shoot the more things you will start seeing. And I will also add that BB will always try to set you on the right path so ask and I’m sure he will tell you what he can.


        • I’m glad I miss interpreted you. Right before my response I had just finished shooting a few groups. I was dealing with a fair amount of pain that day so I spent some extra time breathing down and really focused on relaxing. My normal same hole group was running almost half an inch vertical. After the third group I switched my concentration to my grip and bingo, right back on zero. I would’ve figured it out myself but having recently skimmed over your response helped me trouble shoot my bad technique immediately. Thanks again, I really appreciate people that give advice based in experience and wish people that respond just to let the world know how great they are would stop typing so I didn’t have to wade through them to learn something new.


          • Thanks Ben.
            Sometimes its hard to answer questions correctly because there is so many variables. But like you said. I do try to say something that relates to something I have had happen to me. And if I don’t know about something. Believe me I’m asking questions to.

            Glad it helped. And thank you again.


  3. When I read about the way the gas ram is positioned (body forward), I was confused. Having never held, shot, or disassembled a gas ram gun, I thought this was the logical configuration, and that they were all designed this way. I have since learned that this is not so. Looks like Slinging Lead was ahead of the curve, as usual. ;-)

    BB or Edith: recently I read a comment about a blog BB wrote, “a report about the airguns that I never warmed to”. I can’t remember this blog, nor can I find it after going back several months. Can you please provide a link to this report? I think a person’s distastes says just as much about them as their tastes. The fact that I can’t find it after so much effort makes me think I am losing touch with reality.



  4. Any chance of a sub 12 ft/lb model for the UK? I reckon a UK spec one could be quite a spiffing air rifle.

    TTFN

    Best wishes, Wing Commander Sir Nigel Tetlington-Smythe



    • Hi Goatboy” maybe you can move to the STATES”
      Except for New Jersey,Ill,Mass,Mich,Cal,It took me along time to get used
      to plastic stocks on fire arms and air guns,I tinkered with my R1 and it took a while
      to get it back to normal so the gun wouldn’t fire when closing the barrel,I accidently
      ajusted the part that was in red but all is well now.
      I am curious,How did you get the name Goatboy?


      • I like Bill Hicks, i have a goaty beard, and another reason that i unfortunately can’t print in public. As to moving to the States, well, there are so many amazing places i would live to see there. So maybe one day i will, if I’m allowed.

        All the best,

        Sir Nigel.


  5. B.B.,

    Understand accuracy testing at 10 meters especially when indoors.

    Why only 5 shots for accuracy testing the octane?

    Assume from the crosman premier group that the scope has not moved even though there isn’t a provision for a stop on this gun?

    kevin


  6. I remember firearms training in the military. They constantly told us if your groups wander side to side it is improper trigger control/trigger hold. If the shots wander up and down that is breathing or breath control. I don’t doubt your expertise in shooting since yyou do have more years behind the trigger, but you are also human and prone to forget sometimes. Are you sure you had proper trigger hold and breath control? Even with my decades behind the trigger I find myself every now and again blowing a shot when practicing and needing to correct myself. So I’m looking at your groups and wondering if this might be the source of your shots wandering a bit.


    • John,

      There is no doubt that I do mess up and pull a shot off from time to time. But usually I can call that, because I follow through and focus on the front sight.

      I don’t think I pulled any of the shots in this test. I have mentioned pulling some shots in some past reports, so I will say it when it happens and I notice it.

      B.B.


      • BB
        You did say you shot the factory open sights.

        Just by chance do you think using a scope for the test would of tightened things up a bit. Or if you had a different type of open sight.

        I cant compare anymore with my eye sight. But I’m pretty sure In my younger days that I could hold a little better group with a scope.



          • TT
            Ha ha none of that. More like not enough sleep.

            One of the guys at work is in the hospital this week (I hope only this week for his sake and mine) and I’m trying to cover two 10 hour shifts some kind of way.

            And now your really going to think I’m loosing it. I ordered a sniper airsoft rifle from PA with the special there having right now. And got some Bio BB’s too.


            • GF1

              If you can get it to shoot good enough you might be able to do some bug hunting with it next year.
              I have three cheap airsoft pistols around here somewhere. Not terribly thrilled with them, though.

              twotalon



          • BB
            Yep good point. I always keep forgetting the good group by habit.

            Hmm even if you shrunk the groups by .030″ (not .300″) some of the other pellets would try to start connecting and make a rounder group. How much difference will a hold make if you only change it .010″. By time the pellet goes 10 meters. It will be more than .030″ I would think.


  7. TT
    I got the TSD Tactical SD702 sniper rifle in black and the King Arms .25 gram green Bio BB’s.

    I don’t know what kind of sight I’m going to put on it yet. I think one of my old scopes. Will see.

    I don’t think I will be hitting bugs though.



    • Everything needs a chance. But

      It ain’t so much about whats made in China. Its when the US company’s take away work from us because they think it can be made cheaper and put more money in their pockets by having it made over there.

      Yep I have a attitude about the US company’s doing that. And remember I said some things made in China are good. And if it says its made in China then I know if I buy it I’m probably taking a chance. And that’s my choice and my money that got spent. I just don’t like how that games getting played.

      Just like the new synthetic stock Marauders. It says some parts are made in China. I was going to bring that up on BB’s last report but I didn’t. But it states that about China so somebody that’s buying the gun knows that. And yes it does make a difference to me what parts they are. That would definitely help me make a choice about the Syn-stock M-rod if I was going to pay the price they now want for the gun.

      The airsoft gun I just ordered even bothers me. That’s why I got the cheap $109.00 gun. I really wanted to order the Tanfgolio Gold pistol also. But I believe its like a little above $200.00 dollars or so. So I don’t want to put out the higher dollar for it yet. And I know its not made here. Its made somewhere else. So I want to see what the sniper rifle is about first.

      And now that makes me think. Are there any good American Made or even European Made airsoft guns out there?

      And as far as the Octane goes I have a Steel storm made by Umarex and it has been a good gun. And its not made for the US. Its imported for the US.

      Really no good way to talk about it but thats the way it is.


      • I mis spoke.
        The manual says made in the US with some foreign parts for the Synthetic M-rod. I just assumed China.
        And that’s what BB said the manual for the synthetic stock Marauder says In Part1. But I can’t find it anywhere in the manual. Hmm who knows?


  8. Does anybody know an experienced shooter that has a .177 Octane? I’m both a rookie airgunner and well seasoned marksman and archer. My .177 is shooting impressively accurate and I believe it is the way to go. I know I’m giving up fpe with .177 but with heavy pellets and after alot of break in, the accuracy is far beyond what I expected.


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