Posts Tagged ‘gas spring’
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report is a guest blog from blog reader DMoneyTT. He promised to show us how to fine-tune the Octane trigger, and he’s provided some good photos to go along with his article.
If you’d like to write a guest post for this blog, please email me.
Over to you, DMoneyTT.
Umarex Octane trigger job
As the cost and availability of firearm ammunition continues to keep many shooters from getting adequate trigger time, scores of shooters are turning to airguns to keep their skills honed. Often, new airgunners will be tempted to put down their hard-earned dollars on a rifle offering the highest advertised velocity. Airgun marketing tends to focus on this aspect of performance over all else; but experienced shooters know that accuracy is paramount, and it takes more than just a good barrel and powerplant to deliver tight groups. Proper fit and trigger control are critical considerations when attempting to extract the maximum potential from any rifle.
It’s no secret that the Chinese-manufactured airgun market has seen unparalleled growth and their products are steadily closing the gap between these affordable rifles and their more precise, yet costly, brethren manufactured in Germany, Russia, the United Kingdom and the United States (to name but a few). Many times the differences in quality of manufacturing may be ironed out by the end user. It’s not beyond the skills or tools of the average shooter to dramatically improve the performance of a budget Chinese airgun.
For the shooter who desires all the power of a magnum springer and wants the accuracy to make good use of the velocity but doesn’t want to spend a lot, there are a few good choices. In my humble opinion, the best of these is the Umarex Octane combo. I picked one up several months ago, and it’s been a real joy to plink with and should be excellent for hunting small game, as well. The only downside to this excellent rifle is the trigger-pull. Out of the box, the pull on my rifle registered almost 10 lbs. Others have reported slightly less, so I may have started with an abnormally high pull weight to begin with. There was very little creep (which is a result of minimal sear engagement), and the break was quite crisp. So, a trigger job was necessary, and lessening the pull weight was the only task required.
I would like to say that this does take a steady hand, and careful attention should be paid to the work done on these tiny parts. Any work you decide to do on your rifle should be done with care to maintain the original parts geometry, and it’s always a good idea to carefully test the rifle after any work has been performed. I suggest reading this article before beginning any work to decide if this is within your skill set.
Note from B.B.: Do not work on your gun’s trigger if you do not already have experience working on airguns or are not 100% confident that you can properly disassemble and reassemble the gun and trigger. If you decide to do any part of this trigger tune, you will void the gun’s warranty.
The necessary tools are few.
You will need:
• An Allen wrench that fits the forearm screws.
• A large Phillips screwdriver
• Some paste-type lubricant (synthetic open-gear lube worked well for me)
• A fine wet stone (300-600 grit is preferable)
• A Dremel (or any other rotary tool) with a grey rubber polishing wheel may be used on contact points other than the primary sear and secondary sear interaction point because it’s too likely to round edges.
• A vise to hold the rifle while performing the work.
• Small needlenose pliers or hemostats.
So, let’s begin! Start by ensuring that the rifle is not cocked or loaded. The next task is to remove the stock from the rifle so the trigger group can be accessed. Use an Allen wrench to remove the two forearm screws that attach the action to the stock.
Next, a large Phillips screwdriver is used to remove the screw found behind the triggerguard.
The action can now be removed from the stock. It’s helpful to hold the rifle directly upside down, as the trigger pins fit very loosely and will fall out if the action is tilted to either side once the stock is removed. It’s wise to do all the work over a flat and clean surface that will easily allow dropped parts to be seen and recovered. I chose to mount my action in a vise to allow easy removal of the stock and to gain access to the components of the trigger group. It’s certainly easier to work on the rifle if both hands are free.
Here is the correct placement of the pins in the trigger housing.
Each pin will now need to be removed, and the associated component will need to come out with it. I find that hemostats are very helpful for those with large hands like mine. To help organize the parts, it’s advised to lay them on a white sheet of paper according to their position as they’re removed.
To illustrate the internal layout of the parts, I assembled a jig to hold the pins in the same position they are within the trigger housing. Notice that the shorter leg of the V-shaped sear spring rests against the secondary sear. This is important to reproduce when assembling the trigger group.
Now that the components have been removed from the trigger housing, warm soapy water should be used to degrease all the parts. All contact points between the parts should also be deburred and polished. These areas are circled below in red. I first used a fine (500 grit) whetstone to debur and smooth any rough surfaces. I then polished these parts with a very fine (1000 grit) whetstone. Remove as little metal as possible to get the desired mirror finish and be careful not to round any of the sharp edges. The goal is to make the parts smooth and shiny so they’ll slide against each other with minimal friction but not alter the shape of the parts.
Like the previous photo, these parts are also shown upside down.
Perhaps the most important part to refinish is the trigger adjustment screw. It comes from the factory with a very sharp point that digs into the tertiary sear where it touches. This galls the metal, and there’s significant drag produced when attempting to pull the trigger in its stock configuration. Simply removing this grub screw with a small Allen wrench and rounding and polishing the end that contacts the tertiary sear will reduce the pull weight by 2 or more pounds, depending on the severity of the galling.
I chucked this screw into my drill and spun it against my whetstone until it had a nice, smooth ball end instead of a sharp point. It should look like the image below when you’re done.
If you are not confident enough to tackle this full trigger job, the trigger adjustment screw can be removed from the rifle without any other parts being removed. That allows you to round and polish the end and install it in the trigger to realize a vastly improved trigger-pull with little work involved.
The adjustment of this screw has very little effect on the pull weight or quality because it allows adjustment of the first stage only. This first stage is not a true first stage because the sears do not move as the trigger travels through this stage. The trigger return spring is just being compressed, much like a Gamo or Crosman trigger. Feel free to adjust this screw to whatever position you prefer. There’s no set rule except to not adjust the screw so far in that it eliminates the first stage. That will result in an unsafe rifle that may cause a bear-trap incident (where the piston releases without the trigger being pulled, allowing the barrel to snap shut unexpectedly).
Assembly of the trigger is fairly straightforward and is the reverse of disassembly. The use of a thick paste-type lubricant on the bearing surfaces of the parts will help decrease pull weight as well. I use Mobile One synthetic open gear lube, but most any paste-type lubricant should work. My Octane trigger group was bone-dry from the factory, which certainly contributed to the very stiff pull weight. Use the pictures to help install the parts and pins in their appropriate locations. The hemostats will come in handy again at this point. I installed washers to remove slop from my components but would not recommend it. The difference is hardly noticeable, and it makes assembly much more difficult.
The sum of these modifications should get the trigger-pull down to around 4 lbs. and make it much more smooth and consistent. After averaging the pull weight from 5 measurements, my trigger has settled down at a 3 lb., 2 oz. pull. It’s possible to go slightly lighter with some modifications of the secondary sear geometry; but because of the required precision and the possibility of dangerous results, I suggest stopping at this point. A 3.5-lb. trigger is quite good for a magnum springer and is ideal for accurate plinking and hunting. I know that my groups have improved dramatically, and I’m enjoying the fruits of my own labor when I feel a crisp trigger-break and see targets fall. I hope this helps you get the best from yourself and your rifle.
Please post any questions, comments or tips you have. I’m curious to see what you think.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report is both interesting and a little different. I shot the .22-caliber Octane combo from Umarex at 25 yards and used the Umarex 3-9X40 scope that came in the package. I’ll talk about the scope and mounts first.
The scope is a variable with parallax adjustment from 10 yards to infinity. It features a duplex reticle and comes with 2-piece Weaver rings that have 4 screws per cap. The top of the rifle has a Picatinny adapter clamped on the 11mm dovetails that are cut directly into the spring tube, so the scope rings mounted quickly.
I found the scope to be clear and sharp, and the parallax adjustment to be close to the actual distance once the eyepiece was adjusted correctly. This is one of the nicest scopes I have seen bundled with a combo airgun. I don’t think you need to buy anything other than pellets — lots of pellets.
I sighted-in the gun at 12 feet with one shot, then backed up to 25 yards to refine the sight picture. Veteran readers know I’m purposely trying not to hit the center of the bull, as that erases the aim point.
I was finished sighting-in after 4 more shots and ready to start shooting for the record. The first pellet I selected was the .22 caliber 14.3-grain Crosman Premier that had done so well in the 10-meter test with open sights.
After the first 5 shots, I thought I had a slam-dunk accurate rifle, but I guess I got a little sloppy. Shot 6 went into the same hole, but shots 7 through 10 moved over to the left of the main group. Six consecutive shots went into 0.449 inches; but after 10 shots, the group measured 1.067 inches.
After this group was finished I discovered the scope base screws were both loose. That made the scope loose, as well. I tightened them and checked them frequently throughout the remainder of the test.
The second group of Premiers opened to 1.382 inches. This one is very horizontal, but within it is a tight group of 4 shots that came early in the string. That group measures 0.188 inches between centers.
Following this group, I noticed that both forearm screws had come loose. So they were tightened — a lot! And for the rest of the test, I monitored their tightness closely.
The Octane recoils a lot, and you have to watch all the screws. Once they’re tight, they probably won’t back out for a long time; but the first time you use the gun, they probably need to be tightened just a bit more than normal. At least, watch for them to loosen.
This is nothing new. We have always been told to watch the screws on spring guns that recoil heavily. I just forgot it this time until it became obvious downrange.
JSB Exact Jumbo
Next I tried JSB Exact Jumbo pellets. They did very well for the first 6, then the last 4 wandered over to the right. And when I say “wandered,” I mean they really went places! The group measures 2.822 inches between centers, with 6 of those shots in 0.763 inches.
After this group, I played around with holding my off hand at different places under the forearm, and then some non-standard holds that included resting the rifle directly on the bag 2 different ways. By the time I was finished, I’d fired over 60 shots from a rifle that takes 39 lbs. of force to cock. I never reported that effort in Part 2, like I normally would, so now you know that the Octane is hard to cock — like all powerful gas spring airguns.
I suspected that I was tiring at this point. The term used in competition is I was “blowing up”! The Octane wanted to put them in the same place, but something prevented it. I shot one final group of Premiers — just to see if I could see what it was doing. But that group wasn’t worth reporting. I had clearly pushed past the point of fatigue, so the session was over.
Here’s what’s at stake. Priced at just $200 with a very good scope, the Octane is poised to take its place beside legendary air rifles like the RWS Diana 34 Striker Pro combo. It’s actually $100 less than the 34, yet offers the same power. If it also gives the same accuracy, the Octane suddenly becomes an important air rifle; and if the horribly heavy trigger has a workable solution that the average owner can follow, then folks, we have a winner. So, I want to give this air rifle every chance to compete. It seems to want to do well, so I need to find out what needs to be done.
by Tom Gaylord, a.k.a. B.B. Pelletier
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.
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.
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.
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!
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.
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.
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.
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.
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.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, I’m testing the Crosman MTR77NP scoped air rifle for accuracy at 25 yards. This is going to be a very different accuracy report, for I have no targets to show you. Well, there is one target, but it wasn’t shot with the test rifle.
In the last report, I mentioned that I wanted to mount a different scope on the test rifle and test it at 25 yards. I thought the Bug Buster 3-9x scope would be a good one, and I also shimmed under the rear ring because the rifle was shooting low in the 10-meter test.
I thought the rifle would group about 3 times larger at 25 yards than it had at 10 meters, but I also hoped some pellets might remain tighter than that. What happened, however, was just the reverse. Instead of 3-inch groups I got 5- to 6-inch “patterns.” I won’t call them groups because not all pellets fired even hit the target trap. And when that happens, I stop shooting that particular pellet immediately.
Crosman Premier lites
First up was the pellet I thought had the best chance to do well — the 7.9-grain Crosman Premier. They had done well at 10 meters with just 2 pellets outside the main group. Had they held to my 3X size increase, they would have grouped into about 2.2 inches; but when the third shot landed 6 inches away from shots 1 and 2, and then shot 4 landed 5 inches from that pellet, I stopped shooting.
I checked the scope mount to see that it was still tight. It was, and I’m pretty sure this scope is a good one because it has done well in other tests on other airguns. So, Premier lites are out.
H&N Baracuda Match
Next, I tried some H&N Baracuda Match pellets. But they were no better. They hit the target lower than the Premiers, and 3 shots landed in about a 5-inch pattern. Then, one pellet missed the target trap altogether. I stopped shooting after that shot, but I wasn’t done with this pellet.
I got the Air Venturi Pellet Pen and Seater and deep-seated a couple Premier lites to see what affect that would have. The point of impact changed, but the accuracy didn’t improve. And when the third shot missed the trap, I stopped shooting Baracudas.
The next pellet I tried was the RWS Hobby, which gave such a nice, round group at 10 meters. Two shots landed together, and I thought we were on the right road; then the next shot hit about 6 inches away from them. The 4th shot missed the trap altogether, and I stopped shooting that pellet.
By now, I was in a quandary. Was it me or the gun or the scope? I went back to 12 feet from the target and confirmed that the scope was still shooting to the same point, then I went back to 25 yards and tried an RWS Superdome. I had confirmed at 12 feet that the Superdome would be on paper at 25 yards and the first shot was. It landed high, but in good enough position to keep shooting. The next shot missed the paper altogether and I don’t know where it went. That was it for Superdomes.
What to do?
By this point I was really shaken. My confidence was ebbing fast and I needed to end this session on a high note. So I grabbed my Beeman R8 Tyrolean and a tin of Air Arms Falcon pellets and shot a final group of 10 at 25 yards. This one turned out good, as I expected it would. That’s where today’s target comes from. It isn’t the best group I’ve shot with the R8, but it’s a darn sight better than I did with the MTR77NP. Ten shots went into 0.41 inches.
I need some time to think about why this rifle might be performing like it is. If one of you made a report like this to me, I would tell you to check the scope because that sure seems like what it is. But I did check the scope and found no problems. The one thing left to do is to crank the elevation down all the way and all the way to the left and shoot a group. If it tightens up, then it was the scope. If not, it’s either the mounts or the rifle.
A little tip
What I did with the R8 today is a handy tip to remember. Sometimes the problem is you — or you wonder if it might be. Shooting a good group with a rifle of known accuracy is the best way to rule that out.
by Tom Gaylord, a.k.a. B.B. Pelletier
Just a word
Befoere I get started with today’s report, I want to say something about what happened this weekend. Friday’s airsoft report got a lot of comments. Among them are several questions about the technology of the guns. And some admissions that people didn’t think much of airsoft before they tried it, then they found their opinions changed drastically. That also happened to me, so I can relate to it.
But all you who don’t care for the subject don’t need to worry. This isn’t going to become an airsoft blog. I will continue to report on it at a low level, but I know this is an airgun blog, and that’s not going to change. I want to assure the readers for whom the subject of airsoft is not welcome that we are still going to talk about pellet guns and BBs guns for the most part. I will write a few reports on airsoft now and then, and I trust they won’t upset you too much.
Okay, that’s done. On to the topic of the day!
Today is our second look at the .22-caliber Octane combo from Umarex, and it’s velocity day. Before I get to that, there are a couple adjustments I wanted to make to the rifle. Let’s look at those now.
The first adjustment is the trigger. In the first report, I said the trigger is crisp but heavy. The adjustment screw adjusts only the length of the first-stage pull; so I adjusted it to be longer, and stage 2 decreased. Don’t go too far or the rifle will not cock at all because this adjustment does affect the area of sear contact.
I did go too far and had to call Umarex USA, where I learned that the Octane is supposed to come with a warning tag telling you not to turn in the adjustment screw more than one full turn. I went way past that, so all I had to do was turn the screw back out until the head stood even with the trigger blade — and the trigger was back to working again. For even greater contact, turn the screw so it stands proud of the trigger blade.
The second thing I wanted to adjust is the tension on the action forks because the barrel pivot was too loose. To do that, I normally take the barreled action out of the stock. But with this rifle, you need to be aware that the pins in the trigger are not held in and will fall out of the trigger if the action is tipped sideways. I didn’t know this, of course; and when the first pin fell out, it set me up for 45 minutes of work to get the trigger back together again. It seems that the trigger pins are held in place by the stock. Other airguns I’ve worked on have the same arrangement, and one solution is to put tape on one side of the trigger to hold the pins in place…and keep the trigger oriented straight up and down.
Each of the 6 free (not held by circlips or springs) trigger pins seen here is very loose in its hole and will fall out of the trigger if the gun is jostled or tipped to the side. They’re held in place by the stock. What appears to be a pin at the far right is actually a rivet.
Better still — what you can do (VERY CAREFULLY!) is remove both forearm screws and just LOOSEN the rear screw behind the triggerguard. Then the front of the action can be tipped up clear of the stock far enough to tighten the barrel pivot bolt and nut. I would advise against taking the action completely out of the stock. If you do, know how loose the trigger pins are and treat the rifle accordingly. When the pins fall out, the internal trigger parts start moving around. They’re fairly easy to align with their pin holes, except for the safety that takes a little fiddling since it’s a 2-piece assembly with an internal pivot. My advice is to leave the gun in the stock.
One final tip. When you tighten the stock screws, don’t tighten the rear stock screw (the one behind the triggerguard) too much or the trigger won’t function. It was not tight when I first took the action out of the stock; and I found that if I tightened it too much, the trigger would not work. Umarex told me the screw shouldn’t affect the trigger at all, but I’m just reporting on the behavior of my test rifle.
Now, let’s look at the velocity of the Octane. I’ve selected 3 popular lead pellets and one lead-free pellet.
JSB Exact Jumbo
The first pellet I tested was the 15.9-grain JSB Exact Jumbo. This is a popular and very accurate pellet in many airguns, and I think it may be accurate in the Octane. This pellet averaged 762 f.p.s. in the Octane. The low was 748 f.p.s., and the high was 787 f.p.s.; so the spread was 39 f.p.s. At the average velocity, this pellet produced 20.51 foot-pounds of muzzle energy.
This pellet loaded easily, perhaps too easily. I think it might be a little undersized for the Octane’s breech. That could affect the accuracy. We’ll see.
The RWS Hobby pellet weighs 11.9 grains in .22 caliber and is very tight in the Octane’s breech. It averaged 889 f.p.s. in the rifle with a low of 867 and a high of 902 f.p.s. So the spread was 35 f.p.s. At the average velocity, this pellet produces 20.89 foot-pounds of energy at the muzzle.
I don’t know how Hobbys will do in the Octane, but I suspect they’ll do well because of the tight fit in the bore. Of course, the Hobby is a wadcutter, so accuracy will fall off after about 25 yards.
The .22-caliber Beeman Kodiak dome weighs 21.14 grains, which makes it a very heavy pellet. In the Octane, Kodiaks averaged 682 f.p.s. with a range from 665 to 691 f.p.s. That’s a total spread of 26 f.p.s. At the maximum velocity, the Kodiak produces 21.84 foot-pounds at the muzzle.
My guess is that the Kodiak pellet might also be a good one for the Octane. If so, that’s great because it also produces the most energy of all the lead pellets tested.
Okay, the name of the game with pellet rifles these days is speed, and the RWS HyperMAX lead-free pellet at 9.9 grains is the way to get it. In the Octane, they averaged 1029 f.p.s. with a spread from 1022 to 1075 f.p.s. That’s a spread of 53 f.p.s., so the rifle is probably still burning a lot of fuel. At the average velocity, the HyperMAX pellet produced 23.28 foot-pounds of energy at the muzzle.
The HyperMAX pellet fit the breech very loosely. That’s probably where the extra velocity spread came from, as more dieseling was generated by less pellet resistance. I doubt this pellet will do very well in the Octane because of the loose fit.
The rifle recoils noticeably in both directions, but there’s no vibration, whatsoever. Nearly all rifles with gas springs have a sharp buzz that hits you in the cheek, but the Octane doesn’t. In fact, aside from the recoil, it’s a very smooth-shooting spring rifle.
Remember that I had to adjust the trigger for a very definite stage-2 let-off. That affected the trigger-pull a lot. I was able to adjust it back to a release of 7 lbs., 14 oz. with very little creep. It’s heavy, as I noted before, but I think it’s crisp enough to do good work. We shall soon see!
The Octane IS NOT LOUD!
When I first tested the rifle it was very loud. And the sound persisted for longer than I felt the dieseling of a new airgun would last. But during this test the rifle suddenly became MUCH quieter. Obviously, it had been dieseling and I didn’t know it.
I originally told Edith it was a 3.7 on the sound scale when I tested it, and she adjusted the loudness level on Pyramyd Air’s product page to 4. But now she can hear that the Octane is clearly a 3. I apologize to everyone who was mislead by my earlier report. The Octane is a normal-sounding breakbarrel air rifle.
Observations thus far.
I said in Part 1 that the Octane holds very well in the hands. The weight is biased forward toward the muzzle, and the stock is slender when the off hand rests. Add the smooth shooting to this, and I think the Octane might surprise us in the accuracy test.
I plan on shooting the rifle at 10 meters with its open sights first. That should give us an idea of which pellets it likes. Then, I’ll mount the scope and shoot those best pellets at 10 meters, again. That does 2 things. First, it confirms the pellets are as good as we think; and second, it allows me time to adjust the scope for the second accuracy test at 25 yards.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, we’ll look at the first of 2 accuracy tests planned for the Crosman MTR77NP scoped air rifle. As you know, this rifle has no open sights; so, the first thing I did was mount the Centerpoint 4X32 scope that’s included with the gun. That went quick because the scope caps have 2 screws each, but there was no slippage of the scope in the rings during this test.
The scope is very bright as you would expect a 4X scope to be, but at the 10-meter distance I shot in this test, it was fuzzy. The parallax is fixed for a further distance that isn’t indicated on the scope. I can tell from examination that it’s set farther than 25 yards.
I’m testing at 10 meters today and will take the best pellets into the next test, which will be at 25 yards. The first pellet up was the 7.9-grain Crosman Premier. You will remember from the velocity test that the test rifle shoots considerably slower than its advertised velocity of 1,000 f.p.s. with lead pellets. It went an average of 866 f.p.s. with 7-grain RWS Hobbys.
I discovered that the rifle is shooting low, even with the scope adjusted up high. For the next test, I’ll shim the rear scope ring. That should raise the pellet up far enough.
Crosman Premier lites
At 10 meters, 10 Premier lite pellets made a group that measures 0.721 inches between centers. The group has a main group of 8 pellets within it and 2 flyers, though there were no shots that were pulled. This is a case where a better scope might do better on target because the image was so fuzzy that I might have been off the aim point by 1/8 inch at times.
The MTR77NP fires with a solid thump. There’s no vibration, and the shot cycle is very quick. The recoil through the butt isn’t sharp the way it is on many gas-spring air rifles. And the A2 stock seems to be ideal for handling the recoil of this rifle without stinging your cheek.
Now that I’ve shot the gun for accuracy, I can tell you the trigger-pull is very long in stage 2. The pull length of stage 2 is supposed to be adjustable, but I turned in the screw about 7 full turns and nothing changed. It feels like a placebo screw; or if it does adjust anything, the effect is very small.
H&N Baracuda Match
The next pellet I tested was the heavy H&N Baracuda Match. This pellet showed some promise in the velocity test, and I thought it might do well in this rifle. Ten of them went into a group that measured 0.982 inches between centers. Like the Premier lite, there were flyers outside the main group, though I did not see them when shooting. I’m beginning to think that the next test needs to be conducted with a different scope.
The scope mounts had loosened by this point in the test. The rings remained tight, but the screws that attach the rings to the base on the rifle loosened up. I tightened them and also checked them after every 5 shots from this point on.
Next, I tried 10 RWS Hobby pellets. They went much lower and also to the left. They actually missed the target paper. The group was round and measured 0.826 inches between centers.
Crosman SSP Hollowpoint
I did check the Crosman SSP hollowpoint that was the lead-free pellet I tested in the velocity test, but after 2 pellets missed the target backer altogether, I stopped shooting. Not the pellet for this rifle.
JSB Exact Express
The last pellet I tested was the 7.87-grain JSB Exact Express dome. I haven’t had much luck with this pellet in the past, but I keep trying it just in case. Alas, the MTR77NP doesn’t like it, either. Ten pellets went into a vertical 1.661 inches at 10 meters. Another pellet to not use in this rifle.
Evaluation so far
I like the way the rifle feels when it fires. It has good power and a solid thump when it fires. The trigger-pull is long but not too creepy.
The scope leaves a lot to be desired. I think I’ll replace it with a Bug Buster 3-9X scope for the next test, and I’ll shim the rear scope ring before mounting it on the rifle. That should give the rifle the best chance to do well at 25 yards.
Obviously, the pellets to try are the Crosman Premier lite, the H&N Baracuda and the RWS Hobby. The Hobbys will be at their maximum recommended distance, but they may surprise us.
If you like black rifles and have been considering the MTR77NP, I think it’s worth a look. We’ll know better after the next test.
by Tom Gaylord, a.k.a. B.B. Pelletier
Here’s another new air rifle from Umarex USA. The Octane combo is a breakbarrel air rifle powered by a gas spring. Umarex calls their gas spring the Reaxis gas piston. That title Reaxis signifies that the gas spring unit is mouned in reverse of what’s normal. Instead of the heavier piston going forward with each shot…what would be the tail end of most gas springs…is where the piston seal is mounted. That lowers the reaction mass, which lowers the recoil felt by the shooter. Whether or not it works as advertised is something I’ll test and report.
I’m testing a .22-caliber rifle, at my request. I dislike wasting the energy of a super magnum gas spring on a .177-caliber gun that can’t develop the full power potential, so this is a chance to test this gun the way I would order it. The manufacturer claims a velocity of 1,250 f.p.s. with lead-free pellets and 1,050 f.p.s. with lead. Of course, you know I’m going to test that, as well.
The rifle I’m testing is serial number 00371165. It’s clearly marked Made in China, but don’t ask me what the base gun is. I find that these rifles change their personality a lot when manufacturers have them built to their specifcations, and tracking down the lineage often becomes misleading.
The Octane is a huge air rifle — 48.5 inches overall with a 14.5-inch pull. And it weighs 8.5 lbs. and 9.5 lbs. with scope and mounts. So, it’s longer than an M1 Garand and nearly as heavy. But that weight is biased toward the muzzle, so the rifle holds very steady — a huge point in its favor. And the black synthetic stock has a forearm with a thin cross-section that makes the rifle sink deep into your hand and hold much easier. Laying your off hand under the forearm just forward of the triggerguard provides a stable resting point.
The stock is designed as a permanent thumbhole with a well-shaped pistol grip. The synthetic material is rough to the touch and is checkered on two small panels on either side of the forearm at the place you want to hold it. The buttpad is a very soft and grippy black rubber pad. It’s fitted perfectly and holds on the shoulder without movement. I normally don’t like thumbhole stocks, but this one saves weight, pushes the weight forward toward the muzzle and seems to compliment the rifle very well.
The open sights are fully adjustable, but they have fiberoptic tubes both front and rear. Aiming is, therefore, not going to be precise unless you light the target to keep the fiberoptics from appearing. I’ll initially shoot the rifle with the open sights at 10 meters to see if this is possible.
But this is a combo that comes with a 3-9X40 scope and mounts. The scope has adjustable parallax down to 10 meters, so it’s ideal for airgun use. I’ll report on it as the test progresses.
There’s one additional point to make about the scope. The rifle comes with a Picatinny scope base attached to 11mm dovetails that are cut directly into the spring tube. So the shooter has the choice of using either Weaver rings that will fit Picatinny grooves, or removing the base from the gun and using the 11mm dovetails directly. Either way, though, there’s no provision for a positive scope stop, which is risky on a rifle that recoils heavily. I’ll be watching for any movement of the scope mounts and bases during the test.
Here you see the Picatinny base that’s attached to the integral dovetails. Either can be used to mount a scope, but neither has a positive scope stop because the base is just clamped to the dovetails.
The metal on the barreled action is finished to a satin sheen. It’s shinier than a matte finish, but not as shiny as most European air rifle finishes.
Like all gas springs, there’s a loud crack when the rifle discharges. The Octane has a silencer muzzlebrake they call the SilencAIR. It has internal chambers that might attenuate the discharge sound somewhat. But it’s still a loud airgun — make no mistake! Pyramyd Air rated it as a 3 on the sound scale. I thought it was closer to 3.7, so Edith changed the loudness rating to 4 since Pyramyd Air’s scale has no fractions. It’s louder than most breakbarrel magnums that have coiled steel mainsprings.
You know I have tried the rifle a few times already — just to see how it feels. I found the 2-stage trigger a bit heavy but very crisp. It’s adjustable, so I’ll see what I can do to it in Part 2. I do like the fact that the trigger blade feels fairly straight up and down because that gives me the feeling of control I want.
I read the reviews of the rifle, and they rate it very high. Accuracy is mentioned by several reviewers. I can’t wait to see this for myself, as I’ve not had good luck with the accuracy of magnum rifles with gas springs. I would love to find one that was accurate.
One thing that might work in the Octane’s favor is that the barrel pivots are screws rather than pins. That means they can be tightened. The ones on the test rifle need to be tightened before testing, as the barrel will not stay in position. The owner’s manual also says to clean the barrel before shooting. I will do both things, and report back to you on how it works.
If there’s a category of airguns that I’m dubious about, it’s the magnum springer — especially the one with a gas spring. I’ve seldom seen them shoot accurately. But I’m more than willing to believe they can be good. And if any of them has a chance, this appears to be the one. Given its power and low price, if the Octane is also accurate I’ll sing its praises to the skies!