Posts Tagged ‘trigger-pull’
by Tom Gaylord, a.k.a. B.B. Pelletier
This report addresses:
• Sighting in.
• Corrections to the manual.
• Accuracy at 16 feet, 4 inches (5 meters).
• Accuracy at 25 feet.
Today is accuracy day for the Colt Python BB revolver. I know this is a test many readers have been waiting for, and I think it’ll be worth the wait!
I shot the revolver from a rested position, using a 2-hand hold with my hands forward of the rest and unsupported. My forearms were resting on a cushion, and the revolver was steady in my grip. The target was lit brightly, so the sights were in sharp relief.
I charged the gun with an Umarex CO2 cartridge and shot only Umarex Precision steel BBs in this test. I loaded the cartridges individually, and I found that was faster than using the speedloader. It eliminates some steps that take time.
The first few shots landed too low on the target and also a bit to the left. I first adjusted the elevation of the rear sight and left the windage alone. I did this without consulting the manual, because we all know that the rear sight must move in the direction you want the round to move on target. The gun was shooting low so the sight had to come up — it’s as simple as that. There are directions for elevation adjustment on the rear sight, and they told me to turn the screw counterclockwise to raise the sight. It worked perfectly, but I had to make several adjustments before the BBs were hitting as high as I wanted.
Then, I shot my first 10-shot group. Yes, I shot a complete cylinder and 4 more from the next cylinder. And I’m glad I did. The first group was the best of the day, putting all 10 shots into 0.537 inches between centers. Until I walked up to examine the target, it seemed as though all shots were going into the same hole. But as you can see, the group isn’t quite that spectacular. It’s close, though.
Manual has errors
Next, I wanted to adjust the group slightly to the right, so the rear sight had to be adjusted again; but this time I was stumped. The windage adjustment requires a 1.5mm Allen wrench, while the elevation adjustment is a plain slotted screw. I carry a pocketknife that has a screwdriver, but now I had to find a small Allen wrench. It turns out neither the windage nor the elevation adjustment tools are provided with the gun. I think that’s a mistake because the typical buyer of a gun like this in not likely to have a lot of Allen wrenches laying around (there’s an Allen wrench included, but it’s larger and for removing the cap that holds the CO2 cartridge).
There are no directions for the rear sight adjustment on the gun, so I consulted the manual. That’s when I discovered that both the windage and elevation instructions are backwards in the manual! This is of no concern for elevation, because the instructions are on the gun — but for windage, you have to stop and figure it out yourself.
Then, it was back to shooting targets. This time, I used the slightly smaller 10-meter bulls instead of the 50-foot rimfire bulls I’d used for the first group. The BBs landed higher on this smaller bull, and it appeared that I adjusted the rear sight too far to the right.
The next 10-shot group measures 1.119 inches between centers. The first shot was a flinch that went high and right — out into the white, and the other 9 shots were in the black and measure 0.941 inches between centers. It’s twice the size of the first group and represents the second-worst group shot from 5 meters.
I didn’t change the sights before the next group. Eight of the BBs went into 0.602 inches, but the other 2 shots opened the group to 1.166 inches. It’s the worst group; yet, it contains a remarkable smaller group inside the main group. I think concentration is what determined the group size, more than the accuracy of the gun. In other words — I was tiring out!
Finally, I tried shooting a group at 25 feet. This time only, I fired all 12 shots from 2 full cylinders. The group measures 2.121 inches and demonstrates how quickly the accuracy of a BB falls away as the distance to the target increases.
The Colt Python is accurate
Without a doubt, this Colt Python revolver is an accurate BB gun. I don’t like to make comparisons, but I know a lot of readers want them. I looked at other accurate BB pistols I’ve tested over the years and found this one to hold its own. In other words, about on par with the other accurate BB pistols, and quite a bit better than an average BB pistol.
I like the trigger in both single- and double-action, I like the sights, I like the speedloader and the way the cartridges grab each BB so positively. The power is good and so is the shot count. There’s nothing to dislike, save the lack of sight adjustment tools and the small transposition in the owner’s manual.
If you have a hankering for a Colt Python and cannot or will not spend $1,400 to buy one, this revolver scratches a lot of the itch.
by Tom Gaylord, a.k.a. B.B. Pelletier
This report addresses:
• Loading BBs into the cartridges
• Loading CO2 into the gun
• Velocity in both single- and double-action
• Trigger-pull in single- and double-action
• Shot count per CO2 cylinder
Today, I’ll test the power of the Colt Python BB revolver from Umarex. Thanks to Umarex Director of Marketing Justin Biddle, I was able to begin testing this revolver for you before they hit the market here in the U.S. But they’re now in stock, and your dreams can finally be fulfilled.
As you know, this air pistol loads the BBs into individual cartridges — one BB per cartridge. Where a bullet would go in a regular firearm cartridge, there’s a rubber plug with a hole to accept 1 BB. You can’t put more than a single BB into each cartridge.
The revolver comes with a spring-loaded speedloader that lets you load all 6 cartridges into the gun’s cylinder at the same time. It worked perfectly, but I found that loading each cartridge singly was just as convenient. Perhaps, if I had more than 6 cartridges, the speedloader would become handier. Of course, it’s possible to purchase additional cartridges for this revolver, though at the present time they must come in batches of 6 with a speedloader. Maybe when supplies catch up to demand, they’ll become available individually — we hope.
And, before anyone asks, no, you cannot use other BB-gun revolver cartridges in this revolver. They’ll function, but Pyramyd Air techs have determined that you’ll lose a lot of velocity.
Loading the CO2
As you learned in Part 1, the CO2 cartridge is loaded through a port in the bottom of the grip, rather than in the conventional way of one grip panel coming off. That allows the grip panels to remain tight on the gun — something many readers said they care about.
When I installed the first cartridge, I put a couple drops of Crosman Pellgunoil on the tip to ensure positive sealing. The cartridge sealed instantly, with just a quick hiss as I used the large Allen wrench that came with the gun to tighten the CO2 plug in the bottom of the grip.
As we learned when testing the Dan Wesson BB revolver, there’s a fast way to load the BB cartridges. Spread an even layer of BBs in the top of an empty pellet tin and load all 6 empty cartridges into the speedloader. Then press the tips of the cartridges down into the layer of BBs like you’re cutting cookie dough.
The rubber plugs in the end of the cartridges are tough, and it takes some pressure to pop a BB past the lip. You feel it when it pops into place. After loading, check all your cartridges to ensure all the BBs have been properly seated.
The revolver operates in both the single-action and double-action mode, so naturally I tested both. In single-action, the revolver shot Umarex Precision steel BBs at an average 394 f.p.s. The low was 381 f.p.s., and the high was 421 f.p.s.; so the spread was 40 f.p.s. I allowed about 10 seconds between each shot to offset the cooling effect of the CO2 gas.
In the double-action mode, the revolver averaged 400 f.p.s., with a low of 380 f.p.s. and a high of 410 f.p.s. The spread was 10 f.p.s. less, and the average was 6 f.p.s. faster, indicating the gun is more effective in the double-action mode.
Unfortunately for Umarex, the Colt Python is legendary for the smoothness and lightness of its action. Each one was tuned by human hands before leaving the factory, and there’s no way this CO2 revolver can equal that. You may liken it to a paint-by-numbers copy of the Mona Lisa — you can’t get there from here.
For an air pistol, however, the trigger-pull in single-action (when the hammer is manually cocked before the trigger is pulled) is crisp. It breaks at 5 lbs., 4 oz. In the double-action mode (just pull the trigger to fire the gun each time), it breaks at 9 lbs., 4 oz. which is very light for a revolver. As I mentioned in Part 1, the trigger does not stack (increase in pull pressure sharply near the end of the pull) like a real Colt trigger.
Shooting indoors in a climate-controlled environment at 70˚F, I got 70 good shots from one CO2 cartridge before the velocity began to drop off dangerously. The final shot registered 287 f.p.s. through the chronograph, which is a good place to stop before you jam any BBs in the barrel.
The Colt Python BB pistol is something several people have asked for over the years. It’s as nice as the S&W 586 pellet revolver, in many respects, but sells at less than half the price. The trigger is nice, and the way the cartridges load is realistic. The revolver hangs in the hand nicely. If there’s any benefit from not imitating the Python exactly, it has to be that the air pistol’s 38-oz. weight is lighter than the firearm’s 43.5 oz. in the same barrel length. That’s what you get when metals other than steel are used.
Accuracy testing comes next, and I see those adjustable sights give me the ability to really zero this handgun. Let’s hope they mean it!
by Tom Gaylord, a.k.a. B.B. Pelletier
My rifle is actually a BSA Super Meteor.
Today, you’ll see how I fixed the bad muzzle crown on the BSA Super Meteor, and then we’ll see if that had any effect on the rifle’s accuracy. You might want to read Part 7, again, just to remind yourself of what I faced.
The BSA project has been just that — a project from the start. All I wanted to do was test another vintage spring-piston air rifle for you and report the results, but this particular air rifle has challenged me at every turn. From the time I bought it at the Roanoke airgun show last September, it’s been nothing but a prolonged learning scenario. I won’t bore you by recapping all that’s happened; but if you want to find out, read Parts 1 through 7.
At the end of Part 7, I showed you a nasty muzzle crown, which I surmised was the reason that all the pellets were leaving the barrel with a yaw to their axis. They weren’t tumbling, because every one of them struck the target paper in exactly the same orientation. They were yawing, or traveling forward while pointing off to one side. Because the barrel is rifled, they were spinning on their long axis, but that axis didn’t happen to coincide with their flight path.
The BSA Meteor crown has some serious nicks in it. The dark spot at 10 o’clock is the deepest. Compressed air could escape through this channel before any other part of the pellet leaves the bore, and the jet of air could push the pellet over on its side.
The solution was to crown the bore; but as you can see in the picture, the Meteor’s muzzle is counterbored by more than an inch. In other words, it isn’t where it appears to be from the side. It’s deep inside the barrel, where the theory says it shouldn’t get damaged as easily. Only this one was — perhaps from over-zealous cleaning through the muzzle. Who knows? The point is that it had to be fixed.
My shooting buddy Otho suggested a piloted counterbore to face off the crown true and square to the axis of the bore. And he volunteered to make the pilot, so I slugged the bore for him and found it was a diameter of 0.176 inches. That seemed odd to him because it’s larger than the bore of a .17-caliber rimfire bullet that’s about 0.172-inches. But that’s the difference between .17 caliber and .177 caliber — which is important for airgunners and firearms shooters to know. The pilot he made measures 0.1745 inches and fits the Meteor’s muzzle comfortably.
Otho made the pilot for this counterbore.
The counterbore chucked up perfectly in my portable electric drill. I allowed extra length for the bore to go down into the barrel and touch the muzzle without the drill chuck touching the barrel.
The counterbore is chucked in the drill and set to run true. It sticks out far enough to cut the crown without the drill chuck touching the barrel.
Plugging the barrel
Before starting the work, I pushed 3 fat pellets into the breech and then pushed them with a cleaning rod to within 2 inches of the true muzzle. These will keep the metal chips from dropping down the bore.
I oiled the counterbore and pilot with a good grade of light machine oil before inserting it into the muzzle of the gun. The drill was set on a slow speed, but I can also control the speed by how hard I squeeze the trigger. I wanted a slow steady turn without putting much pressure on the drill. The counterbore is sharp enough to cut the soft barrel metal without a lot of encouragement.
The drill is set to run slow, and I’m also slowing it more with the trigger. You don’t need speed for a cut like this.
After about 10 seconds of cutting, I removed the counterbore and cleaned the new crown with a cotton swab. There was a band of bright metal around the muzzle where the counterbore had cut. Upon close examination, I could still see gouges in the bright band. The gouges were deeper than the first cut.
The new crown is bright after the first cut, but there are still gouges that need to come out.
I cleaned the counterbore with a swab and oiled it again. Then, I made a second cut on the crown. This time, I felt the drill pulse as the cutter removed the uneven metal. It became smooth, and I knew the cut was finished. When I cleaned and inspected the new crown this time, it appeared smooth and even. The job was done.
I apologize for the blurriness of this picture. Focusing on the crown is very difficult when I’m also trying to light it from the same axis as the lens is pointing. The lens is about one inch from the end of the barrel, and this was the best picture I got. There are still some faint marks on the crown. After examination with a loupe, I didn’t think they would be a problem.
At this point, I felt the crown was as clean as I could get it. And there was a simple way to see if this had made a difference. I drove the pellets in the bore out the muzzle and a few steel chips came with them. Next, I shot two RWS Hobby pellets offhand from 12 feet. If the crown was good, they would cut the paper perfectly instead of hitting sideways. And that’s what happened.
So, I backed up to 8 yards and shot 2 more shots from an improvised rest. These 2 pellets landed very close to each other and also showed no signs of tipping. I felt the job was done.
The two lower shots were from 12 feet. They confirmed the pellets were hitting the paper straight-on. The two upper shots were from an improvised rest at about 8 yards. They told me the crown is probably working.
Now for the test!
The test is a rerun of the Part 7 accuracy test. I used every pellet from the last accuracy test and shot at the same 10 meters.
Ten Eley Wasps went into 2.256 inches at 10 meters.
If you compare these targets to those in Part 7, one thing jumps out at you. None of these pellets tipped when they went through the paper. So, crowning seems to have solved that problem!
But the accuracy seems no better. The Hobbys did group better in this test, but the Falcons grouped worse. With groups this large at 10 meters, I’m not willing to say anything has improved. I’ve had cheap Chinese air rifles group better than this.
I have one trick left up my sleeve. I’ve noticed that the Meteor rear sight seems hinky and difficult to adjust, and I suspect it jumps around as I shoot. It’s not loose to the touch, but I don’t trust it to hold zero.
I’ll do one more test of this rifle with either a dot sight or with the See All Open Sight if I can get it mounted to the Meteor. If that doesn’t work, I’ll probably abandon this air rifle as a bad investment.
by Tom Gaylord, a.k.a. B.B. Pelletier
My rifle is actually a BSA Super Meteor.
I’m headed to Las Vegas this weekend for the 2014 SHOT Show, so I’m asking veteran readers to help the newer readers more than usual. And I thank you in advance.
Tuesday’s blog will have something very important. It’s the first day of the SHOT Show, and I’ll show you something brand-new. It’s a pretty big deal, so it’s worth a look. Now, let’s get to today’s report.
Today, we’ll look at the accuracy of the BSA Super Meteor Mark IV that I’ve been working to restore. This report was never supposed to be an ongoing saga. It was supposed to be a quick 3-part look at a vintage air rifle, but the Meteor that I bought at the Roanoke airgun show last September turned out to need almost one of everything. So, I hunkered down and went to work.
I said in one of the earlier parts that fixing up an old spring-piston rifle is a lot like rebuilding an old tractor. Man, was that ever a prophesy! I had no idea that I would have to get down into the guts of the rifle to get it shooting again; but if you’ve followed along on all the earlier parts, you know that’s exactly what happened. Now that the old girl is shooting like she should, let’s see how accurate she is.
This is a vintage spring rifle with open sights, so I like to begin shooting those at 10 meters. Since I have no idea how accurate or inaccurate they are, it’s best to start close. If the groups show some promise, I can always back up to 25 yards and shoot a second test.
I figured a vintage airgun deserves a vintage pellet, so I broke out some obsolete Eley Wasps in .177 caliber as the first pellet. The first 2 shots were to sight in, and shot #1 was low, so I tried to adjust the rear sight up using the adjustment wheel. Alas — it didn’t move the sight! The backup plan was to loosen the rear sight blade and slide it higher. I also noted that the whole rear sight unit needed to be snugged down, so that was also done.
These .177 Eley Wasps are from the same timeframe as the Meteor rifle.
Loosen the 2 screws and slide the sight blade up to raise the point of impact.
Before we proceed, a word about .177 Eley Wasps is in order. Many of you know that the 5.56mm (.22-caliber) Eley Wasp is a particularly fat .22-caliber pellet. It’s often the best in vintage airguns whose bores are on the large side. But the .177-caliber Wasp is not an oversized pellet — at least not the ones I have. I often choose these pellets for guns with larger bores such as the Meteor, forgetting that these aren’t the best or biggest .177 pellets around.
I shot only 8 pellets at the target because the group grew to 3.559 inches between centers, and it didn’t seem worth my time to finish. But that wasn’t all I noticed. Most of the pellet holes are ripped out to the right, as if the pellets were not traveling straight. We know from the previous velocity test that this rifle now shoots fast enough to not tear target paper when the pellets pass through, so this tearing had to have been caused by the pellet’s orientation and not its velocity.
It only took 8 Eley Wasp pellets to convince me that this was not the right pellet for the Meteor. Notice the tearing of the paper! It’s all in the same direction. I’m cutting off parts of the bulls in this photo because they contain another group from another pellet.
Crosman Premier lite
These results were enough to convince me to use modern pellets in the Meteor. The next pellet I tested was the Crosman Premier lite. This time, I fired all 10 pellets, and the group was much smaller than before, but it still measured 1.73 inches between centers. That’s horrible for any air rifle at 10 meters!
What was even more surprising is the fact that the Premiers also tore paper to the right of the main pellet hole. In fact, they tore in exactly the same place!
It looks like 9 holes, but there are 10 Crosman Premier lite pellets in this group. It measures 1.73 inches between centers…and notice the tearing of the target paper in exactly the same way that the Eley Wasp pellets tore it.
If the pellets were tumbling in flight, the tears would be randomly scattered around the main hole because the tumbling pellet would change its orientation all the time. But because they are all in the same place, it looks like the pellets are tipping as they exit the muzzle and flying straight to the target in that tipped orientation. Hmmm! Have to think about that.
Air Arms Falcon
The next pellet I tried was the Falcon from Air Arms. I selected this pellet because the heads were sized large, at 4.52mm. They have the largest heads of any .177 pellets I have.
They put what looks like 9 shots into 1.863 inches between centers. Once again, several of the holes are torn on the right side.
The final pellet I tested was the RWS Hobby. This is a large wadcutter that sometimes is very accurate at 10 meters. But not this time. Ten went into a group that measures 2.05 inches between centers. They also tore the paper to the right of the main pellet holes.
I knew something was wrong with the rifle because these pellets all fly at different speeds. There’s no way a tumbling pellet can tear the paper in exactly the same place when they all get there at different times. For even one single type of pellet to do that is hard to believe, but for 4 different types…it’s impossible. The pellets have to be leaving the muzzle tipped on their edge and remain in that orientation all the way to the target.
I know that most of you have guessed what’s wrong with the rifle by this point, but I hadn’t. Of course, I didn’t have someone pushing my nose into the facts like you have in this report. It wasn’t until my buddy Otho came by for a visit. I showed him the targets (because he has an interest in the Meteor, as you recall), and he said, “I’ll bet that barrel needs to be recrowned.”
Oh, my gosh! How could I fail to see that? Of course that was the problem. When I brought out the Meteor for him to look at, he saw it right away. I bet you will, too. The muzzle is backbored by more than an inch; but with a tactical flashlight, we were able to look down inside.
See the dark spot at 10 o’clock? It appears to be a nick in the muzzle. How it got there I don’t know, but it should be fixed.
The saga continues!
Yep, this Meteor is like an old tractor, all right. Just when you think you have the thing running and looking spiffy — the magneto quits. These days, there’s only one old man in Kansas who can repair them. Actually, I protesteth too much because I really enjoy working on this gun. It wasn’t made in China, yet it has turned out to be even worse than most of the very poor-quality Chinese airguns I’ve tested in the past.
In truth, there’s a lot of great engineering in this rifle, as well as a ton of abuse. You BSA Meteor owners out there know that I’m not purposely beating up your favorite airgun. It’s just that it challenges me at every turn. But that’s a large part of what makes this hobby interesting. After all is said and done, I’m not upset.
OK, take that report on a Friday and run with it! Remember, I’m on my way to Las Vegas and cannot answer as many comments as normal.
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.