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Education / Training Umarex Fusion CO2 rifle: Part 1

Umarex Fusion CO2 rifle: Part 1

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


Umarex Fusion CO2 rifle
Umarex Fusion CO2 rifle.

One of the perks of visiting the manufacturer is getting to try new airguns. I visited Umarex USA last February to film my parts for this year’s American Airgunner show, and we were also given a tour of the facility in Fort Smith, Arkansas. We got to shoot many airguns and even a couple firearms, but the one gun that wasn’t quite ready was today’s subject gun, the .177-caliber Umarex Fusion CO2 rifle. Sales Director Justin Biddle (JB) told us the gun was going to be incredibly quiet. I really wanted to hear it perform, but it wasn’t going to happen because the gun just wasn’t ready.

Shouting about silence
Well, now I have a Fusion rifle in hand, and I get to test it all I want! I’m testing rifle number 00360129. Like all Fusions, this rifle comes in .177 caliber.

I told JB back in February that Pyramyd AIR was very particular about the sound ratings shown with the descriptions on their website because, sometimes, they’re all a customer has to go by when buying an airgun. As the saying goes, “Once burned, twice shy,” so if there’s any question, no sound rating is accepted unless the Pyramyd AIR tech team or I get to listen to the discharge of a production gun. We don’t want the customer who may be making his once-every-five-years purchase to be misled!

But I have to tell you — the box this rifle comes in touts the 5-chamber SilenceAir silencer attached to the barrel, and the rifle’s ultra-quiet operation is mentioned at least once on most of the box sides. They’ve gone so far as to put a video ad on the Pyramyd AIR website, touting how quiet the rifle is. So, in all likelihood it is very quiet. Because, if it isn’t, it would open the door to a tidal wave of criticism! I’m prepared to be amazed.

There are other reasons for wanting to test the new Fusion, as well. It isn’t every day I get to see a new CO2 rifle. They don’t come along that often, and each new one seems different than the few we already have — unlike the introduction of yet another 1,400 f.p.s. breakbarrel magnum springer!

The rifle is a bolt-action single-shot, so in my mind that puts it in the Tech Force 78 category. Pyramyd AIR no longer carries that model, and there are very few single-shot CO2 rifles to be had.

The rifle
Even though the black stock is synthetic, the Fusion is not a featherweight. It weighs 5.71 lbs., which is certainly light enough, but it’s also enough weight to let you know there’s something in your hands. I would call this a handy rifle, in that sense. The dimensions are large enough for an adult (14-inch pull), yet the stock is also thin where you naturally grab it; so, think of this as the Diana 27 of CO2 rifles.

The rifle is just over 40 inches in length and balances with a slight bias toward the muzzle. The silencer is one inch in diameter and permanently attached to the rifle. The rifled steel barrel is a whisker over 17 inches long, and ends where the baffled silencer begins. It appears free-floated, but it does contact a barrel band that attaches it to the CO2 tube below.

The entire rifle is matte black. The stock is dull, and the barreled receiver is blued to a matte black sheen.

The bolt requires a fairly stiff pull to cock the action, so you’ll want the rifle against your shoulder or something firm when you shoot. A tray in the receiver accepts the pellet and helps guide it into the breech.

Umarex Fusion rifle pellet tray
There is a pellet tray in the receiver, similar to what a single-shot .22 rimfire uses to guide the cartridge into the chamber.

The buttstock has a very straight line — as opposed to a stock that drops at the comb. Therefore, it will accept a scope more readily than most rifles. The stock fits me very well. In fact, my off hand likes how the stock narrows just ahead of the triggerguard.

There are no open sights. The rifle comes with a 4×32 scope and rings; so, you do have sights, but they have to be mounted. I’ll cover that process in Part 3.

The trigger isn’t adjustable. It’s two stages with a long, light first stage and a long second stage that has some creep. The safety is automatic and comes on every time the rifle is cocked. It’s a sliding switch located on the top right side of triggerguard, just forward of the trigger. It can be applied and taken off at any time and appears to block the trigger from moving.

Umarex Fusion rifle safety
The safety switch slides forward when the rifle is cocked. It can be applied manually at any time.

This rifle favors right-handed shooters. The stock is ambidextrous, but the bolt handle operates only on the right side of the receiver.

Charging the rifle
The Fusion needs two 12-gram CO2 cartridges each time it’s charged. They’re loaded end-to-end, similar to other CO2 rifles, but the charging mechanism isn’t as straightforward as you’re used to. There’s also a pressure-relief valve in the charging cap that lets you exhaust remaining pressure in the gun at the end of the useful charge. But that valve complicates the charging process just a bit.

To charge the gun, you first unscrew the cap that covers the pressure-relief valve control knob. Those threads are left-hand, so the cap comes off by screwing it clockwise. Then, the control knob is screwed down as far as it will go and then backed out three full turns. This closes the exhaust valve, making the CO2 reservoir cap ready for filling.

Use some kind of oil on the tip of each CO2 cartridge before dropping it into the rifle, and also spread some oil on the o-ring that seals the rifle’s cap. The instructions say to use RWS Chamber Lube; but since I had none of that, I used Crosman Pellgunoil.

Umarex Fusion rifle CO2 cap
The Fusion CO2 cap is more complex than the usual cap. The cap has been removed. The knob at the right is to exhaust the residual gas when it’s time to change the cartridges. It’s shown in the closed position, so the cap is gas-tight.

With both cartridges inside the tube, I screwed down the cap, and gas started hissing somewhere. I’m used to hearing a brief rush of gas, then the solid sound of the seal doing its job, so this hissing threw me for a loop. I played with the pressure-relief valve knob — unscrewing it farther. The hissing continued, so I screwed in the cap several more turns (against great resistance), and it finally stopped. That was the longest period of gas release I’ve ever heard from a CO2 gun during filling; so after shooting it several times, I exhausted the remaining gas and tried again with 2 fresh CO2 cartridges.

It happened the second time, too. Gas was exhausting for at least 30 seconds as I tried to tightly screw down the cap, but the cap got almost too tight to screw. This time, I knew the pressure-relief valve was closed; and I even opened and closed it during the procedure, just to make sure. I finally put my back into it and got the cap secured, but not before a lot of gas was lost.

I believe the problem is the o-ring on the cap is made of material that’s permeable to CO2 gas and swells rapidly in its presence. It swells enough when the gas is first released to make the cap difficult to screw in far enough to seal the chamber. We had problems like this with the old o-rings on CO2 guns years ago; but when the new non-porous o-ring material came to market, the problem stopped. This is something that needs to be looked at by the manufacturer. I will keep an eye on it as this test proceeds, and I’ll report my findings to you.

The box says to expect 750 f.p.s. with alloy (meaning lead-free) pellets and 700 f.p.s. with lead. I’ll try it with both, and I’ll try several lead pellets because this will be of interest to potential buyers. If it really gets that much velocity, this rifle could be used to eliminate small pests up to the size of small rats at close range.

Since I’ve shot the rifle already, I’ve heard the discharge sound. But I’m going to wait until the velocity test to report it. You can ask, but I won’t tell. Gotta save something for the later reports!

We don’t get a new CO2 rifle that often, so this one seems to hold a lot of promise. Velocity testing and a report on the report are next.

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

86 thoughts on “Umarex Fusion CO2 rifle: Part 1”

  1. This rifle favors right-handed shooters. The stock is ambidextrous, but the bolt handle operates only on the right side of the receiver.

    Not necessarily a drawback. I’m a lefty and I’d honestly be lost on a left-handed rifle.

      • B.B.,

        Bummer about the sealing issue. I hope that gets sorted out easily.

        I’m left-handed, too, and I used to think that I’m irreversibly conditioned to reaching over the whole rifle to pull the bolt (if it’s easy) or unshoulder it for cocking (if it’s stiff), but after trying a buddy’s airsoft sniper rifle that had the bolt converted to left-handed, I was in heaven. It took me two shots to become completely used to it.

        I noticed that the ramps, for lack of a better word, that guide the pellet into the tray are arranged for right-hand pellet-handling. That would not be a deal-breaker for me, although the arrangement looks like it will make loading VERY easy for the right-handed shooter. Frankly, it irks me when I see something which appears to be a great design for righties that is not also available for lefties.

        I am looking at this gun as a possible alternative to my Hammerli 850, which I use a lot in the basement in the winter. The 850 is loud and an annoyance to my wife and our cats, so if this is genuinely very quiet, I might go for one.


        • Sounds like the same issue with the Crosman Nightforce from a few years back (and the reason I eventually got rid of mine). It used the .88gr CO2 cartridges and as time went by it was just impossible to get the cartridge screwed in tightly enough to stop the gas from escaping. I had it replaced once under warranty. The replacement worked well for a couple dozen cartridges then started having the same problem.

          • I have a couple Nightstalkers, and along with my Hammerli 850 and my MK II Wlather Lever Action, which also use 88 gram bottles, I always take some sand paper or a buffer wheel and lightly go over the male threads on the bottle, followed by carefully wiping it all clean. Then, in addition to the big dab of Pellgun Oil I put on the tip, I also rub some on the male threads, making them nice and slippery.

            I have no idea whether what I’m doing helps accomplish or prevent anything, but it just seems like a good idea.


  2. I have glanced at this gun on the PA site.
    So I’m glad your doing the report BB. And I remember that I was reading about the fill cap some where. And it seemed like it could be a bit tricky to operate.

    And what brand scope comes with it and is it pretty clear/crisp or whatever you want to call it when you look through it?

  3. I should imagine the lads and lasses at the Umarex Boys Club should be getting quite excited about this one, it certainly got my attention. God only knows when it will hit the UK market, but I’m sure it will get full coverage in the airgun mags when it does.

    The idea of venting the useless gas when changing Co2 is an attractive selling point, but it be a shame to have to source another O ring after handing over ones cash. Personally i think this rifle is quite the looker and would sell on that alone, as you said there are very few Co2 rifles out there compared to say springer’s for example. I can even see room for an after market magazine if they prove popular, something that connects to the scope rail, rotates, and drops the pellet into the tray. But I’m getting ahead of myself here, but i do find myself looking forward to the rest of the reports with some excitement.


    Best wishes, Wing Commander Sir Nigel Tetlington-Smythe.

  4. It seems like the reason it needs two CO2 cartridges to charge it is so you will have some CO2 left in the gun to shoot it.

    This should be a VERY obvious issue to even the most dense marketeer at Umarex. It probably is, that’s why all the hype. “Maybe we can drown out all of the issues our product has if we shout loud enough about how quite it is.”

    Very likely what happened is as production was about to begin, someone in purchasing did a Six Sigma project. Rather than correcting the issue at the company’s expense, it was decided to send them out as is and let the customer go to the hardware store at his own expense to correct their mistake.

    This is the reason that although I have been seriously considering purchasing a RWS 34P Pro Compact, I hesitate. It says Umarex on the side. Very likely the 34 is no longer the 34.

  5. This was sent to the wrong address, so I have posted it here for the sender.

    Hi Tom,

    I love your blog. I have been out of airguns for a while, but I am getting back into it again. I have an older Beeman R9, a couple of Benjamin 392s, a Daisy 853. I used to have a FWB124, but that one is long gone.

    My question is what happened to Beeman Precision Airguns? I buy my guns and pellets from Pyramid, but I looked at the beeman site, and they dont sell any of the classic R series. I see that Pyramid does. Did they lose some contract with Weirach? Their site is a dissapointment.

    Ok, I have been thinking of the HW90. I have no trouble cocking the R9, is the HW90 that much harder to cock? I am planning on using it for hunting and long range target shooting. I want to get it in .22 I am a lefty too, is the stock ok to shoot lefty even though there is a cheek rest like my R9?

    Thanks again,

    • Jim,

      Beeman Precision Airguns was sold to the Chinese a few years ago. They have an agreement with Pyramyd AIR to continue the sales and service of the German Beeman-branded guns and the Chinese are selling their own Chinese-made Beeman-branded guns through discount stores.

      All support of the Beeman brand will now be done by Pyramyd AIR.

      Yes, the HW 90 with its gas spring is MUCH harder to cock than an R9. Most guns with gas springs are hard, because of how gas springs work. I believe you could use the rifle left-handed.

      I don’t answer emails sent directly to me, because there are so many readers on this blog who want to know the exact same things as you. That keeps my emails down below 100/day, for the most part.


    • Jim,

      I measured the cocking force on my HW90 and it is a little over 50 lbs according to my scale. The gas spring is at full pressure and the gun generates around 20 ft/lbs muzzle energy depending on the pellet. The Elite trigger is nice, but a little mushier than a Rekord. The muzzle brake/weight extends the muzzle and helps some with the cocking force required. The HW90 is a heavy,big gun! But it’s nice to shoot, pretty accurate, and more forgiving of hold technique than most of my other springers. Hope that helps.


      • Thanks Dave, that does help. That will probably be my next one. What scope are you using? Do you think that the Bugbuster 3×9 would be up to taking the recoil? I was comparing that scope to the Bushnell 4x12AO.

  6. Tom, the leakage problem is not with the seal on the cap. The inside end of the cap has come unscrewed. If you look at the picture you will see the gap between the part that has the o-ring on it and the end piece. This has made the cap longer and it is not allowing the o-ring to slide past the relief hole in the tube…..

    Back the relief valve under the cap off until it spins freely before inserting cylinders, if do not plan to use the valve to exhaust the last bit of gas you can remove it.

    • Mike,

      Thank you for this! But I did notice that the o-ring IS made of the wrong material and it does swell in the presence of CO2 gas. Also, Umarex tells me they are aware of the need for a materials change in this o-ring.

      I will check the cap when I open it the next time and adjust it as you recommend.



  7. I did give this one a second look . Really.
    Then I saw the country of origin.
    So let’s see….
    Need a different seal of unknown size, and probably a different scope.

    No sale.


  8. Nice looking rifle. While I really like CO2 guns, I’m not a fan of the dual 12g cart models. And, I thought I read somewhere that this rifle gets a ridiculously low number of shots from the carts—something like 20 or 30 good shots. If this is true, it relegates the gun to hunter class and not target shooting. Definitely a deal breaker for me.

    And, I really don’t understand why Umarex would let an apparent factory defect (wrong o-ring) out the door for consumption.

    • Just look at the glitches that computer software is sold with, getting it out the door NOW is more important, “we’ll fix the issues later” seems to be the moto, after all the product was indeed sold so money is coming in, if there are issues and people don’t fix it themselves they’ll fix it under warranty.

      Lets say 100 rifles are sold, 40 people use it like that, 30 fix it at their expense, 20 return it to the store for various reasons valid or not and you’re left with only 10 rifles to fix, you send the buyers a new o-ring with instructions and voilà, done.
      Even if you reverse the numbers and you have 40 o-rings to send out, you still have 100 sold rifles.


        • Sounds just like the photo industry the last 20 years ago.
          Before that a camera would be introduced after a year of testing and be just about perfect out of the box. This was when Nikon and Canon introduced new models every 4+ years.
          Now they come out so fast…they do a limited time in pre-production testing and then thow it into the marketplace and wait for the complaints to roll in. A month afterwords all the firmware updates hit the internet so you can download them and make your camera work the way it is intended to.
          Damn annoying!!

            • Lets not be too hard on the Hubble telescope folks. They couldn’t exactly test the thing at nearly absolute zero temperature, at nearly zero gravity. Consumer product manufacturers don’t have these excuses.

              • Especially as part of the Hubble problems were that the mirror has a nice perfectly smooth curvature, according to the test rig.

                But the test rig itself was just far enough out-of-spec to result in the mirror not focusing where it was supposed to.

                Visualize drawing a 5″ radius circle using a compass with micrometer adjustments — but setting the 5″ radius using a wooden school ruler with a worn off end.

            • Gentlemen,

              The problem was not that the Hubble was difficult to test. The problem was, it wasn’t tested!

              I worked on the project, and a series of tests were skipped because of budget overruns and because, after all, Kodak was doing the important optics! And they are Kodak!

              One thing you can count on is that a government project manager will do anything to be seen saving money. And that was what happened. Afterwards, there was the usual finger-pointing and the guilty were probably promoted — not because of their contributions, but so they would be in a position to never be able to make that kind of mistake again. That is the mantra of government project management.


    • If it really is getting 700fps with lead, it probably needs two cartridges just to provide a fast enough expansion of the CO2.

      Granted, my CO2 experience with short barreled pistols, but 700fps is around twice the velocity; the cartridges are on their side meaning some liquid CO2 may be filling carrying tube…

  9. Nuts! I was looking forward to this one! I’ve been pretty impressed with the 1077 I bought for my daughter, it has functioned flawlessly through thousands of rounds now but doesn’t have power for anything more than paper punching. Was really hoping this would be the ‘adult’ alternative.
    I think I hear a Hammerli 850 calling my name!

  10. I like this one, it would need to be slower (.22 caliber maybe?) and without the silencer for it to be available here but I think it looks nice, especially for the sub 200$ price, add a nicer scope and you could have a pretty nice recoiless rifle for 200$.

    I like the big bolt, I can never get the itsy bitsy bolt, I like them to be nice and easy to handle, not flimsy little pieces of plastic. Not everyone has tiny kids fingers.
    And I totally agree with goatboy/Sir Nigel, I think this thing begs for a mag! A Marauder like mag would be perfect for this thing.
    Tom do you think it may happen?

    Can’t wait to see if this thing will be accurate.


  11. BB,

    something this blatant is beyond my comprehension. A faulty seal is not a hidden defect that could be overlooked by the Umarex engineers and marketing people as they test this product. To follow up on J-F’s comment on software, those products are so complex that a hidden fault could easily surface since the software might be used in a manner by the end-user that was not contemplated by the developers. But overlooking a primary fault that everyone would incur (inserting and charging the rifle with CO2 cartridges) really begs my credulity. Either there is a defect in the rifle you have, the instructions don’t properly explain the loading procedure needed or Umarex’ engineers and developers are incredibly inept!

    Sorry to be so blunt.

    Fred DPRoNJ

    • ” Either there is a defect in the rifle you have, the instructions don’t properly explain the loading procedure needed or Umarex’ engineers and developers are incredibly inept!”

      Maybe a case of “all of the above”?

      Software comes out with known faults, it’s just too long to fix them, so the software comes out with problems and it could be solved a few days later or in a few montsh or never.
      Unless you have a Mac of course.


    • Another possibility is a last-minute change in the oring spec by Umarex or the supplier. Possibly the original design used an oring that sealed immediately but was found to make the cap difficult to thread on. So a smaller, expanding seal was used instead. Easier than changing the hard bits.

      Either way Umarex should have recognized the issue – CO2 is not free and people do not like hearing the gas hissing away. Perhaps a high percentage of returns for this “problem” will cause them to implement a real fix. It may have taken a little more time to get the gun to market but buyers would prefer something that works properly the first time. It is cheaper in the long run.

      Paul in Liberty County

    • Fred,

      I don’t think it’s a case over overlooking a fault. I think the seal was chosen intentionally for what it does. The designers may not have seen the same fault I caught. In other words, maybe it doesn’t happen with every one of them?

      But as I said in the report, we’ve been down this road before and we don’t need to be here again.


  12. B.B., been waiting for what seems like a while for this report! Looking so forward to it. I too am concerned about the quality. I was with the thought that this was at one time the Ruger Co2 rifle that never really came to be due to quality issues. If this is the same rifle, I too was hoping they would “fix” all the bugs before putting it out. I’m still like the idea and looks of the gun, that said, I will now have a wait and see attitude. Oh and I know Justin Biddle (JB). His is a very nice guy! Thanks again and looking forward to part 2.
    PS. how loud did you say it was? Can’t blame a guy for trying.

  13. It’s a fairly interesting chinese made gun, but for several reasons it will never find it’s way into my gun racks. First it has a silencer so it will be tough to get in Michigan. Secong it is chinese made and I’m trying very hard to get rid of all my chinese made guns since they are poorly made. This gun might be new but chinese manufacturing being what it is with no quality control to speak of and chinese companies making everything out of the cheapest possible materials that might be toxic as well I won’t have it. It seems like you already found a manufacturing problem. It appears the valves or seals are made as poorly as possible and leak. A leaky gun is fairly useless. If you have to struggle with the gun to make it hold co2 it’s a poorly made gun.

  14. I just read the manual on loading the cartridges.
    And it says multiple times to back off the air bleed if CO2 still leaks. It says the retaining ring punctures the seal on the cartridges.
    And the air bleed is supposed to be bottomed out then backed off 3 turns before you even put it in the gun. That makes me think that I would even turn it out more than the 3 turns and then try and see what happens.
    I knew I read some where that its a tricky procedure. With out a gun in front of me who’s to say that their procedure is even correct.

  15. Edith
    The reply I just made to BB.
    It did that redirect error page or whatever it is.

    Had to do what I said before.
    Page back, click on another topic then click on the topic I replied on and it will be there then.

  16. Mighty mysterious. I don’t recall any mention of serial numbers of test guns before, and I’m going to include that this probably a favorable indication than otherwise…. As for the sound, I’m looking to see if the hype measures up to B.B.’s highest standard of a pen being dropped onto thick carpeting attained by the Marauder.

    That CO2 hissing can be mysterious. I always use EXACTLY the same number of shots in my CO2 guns. But in a few cases, the used canister will keep on hissing. Sometimes, I wonder about asphyxiation or ill effects from all this gas in my small enclosed shooting room (unventilated during the shooting sessions).


  17. Hi B.B., I had a quick question and I know you are the go to source for airgun information. I recently purchased a new in box Daisy powerline 2001 35 shot repeater CO2 rifle, and a like new Crosman 3100. I can’t seem to find any information on either one of these rifles, do you have any information as far as value, accuracy, problems etc? Thank you.

    • Chris,

      I have nothing on the Daisy. I had a Crosman 3500, which was an Anschutz breakbarrel, and it wasn’t too accurate. I have never seen a 3100, but I’m thinking that it’s like the 3500. If so, don’t expect too much from it.


      • Thanks for the input, but mine looks nothing like the 3500, it’s actually a handsome rifle, with globe sights. It was made in Spain, not sure by who. The Daisy isn’t nearly as much of a looker, but couldn’t pass up such a unique piece. I didn’t spend enough on either one to ever have it make much sense to get rid of them. The 3100 is plenty accurate though. If I had to hazard a guess I would say about 570 f.p.s. and not one trace of springer twang.

  18. B.B.

    I noticed in the manual that it says to put the chamber lube on the o ring as well as the powerlets. Maybe that will stop the leaking and/or keep the o ring pliable. I hate it when brand new products start out defective. It makes my stomach churn.

    By the way, I enjoy CO2 rifles. I have both the Hammerli 850 and the Walther Underlever and they are both a lot of fun. They are not very good for target shooting but are great for plinking, although the Hammerli can be quite accurate.


      • I missed that in your report. I didn’t know that about C.O.2 files. Neither of my rifles has an o ring on the cap. Actually, neither of them have a cap anything like this one. Just covers.


        • Single cartridge systems only have to push the cartridge against the puncture/seal surface — so the other end is just some sort of support/screw.

          I have the impression this double cartridge system uses cartridges pointing in opposite directions.


          That means there are puncturing systems at both ends — and that there has to be a way for the CO2 to get from the end of the carrier tube to the valve. IOWs, the punctured cartridges “drain” into the carrier tube itself, and are NOT directly impinging onto the firing valve.

          I could be wrong, but this IS the mental image I get from seeing the parts.

  19. Not sure if its helpful or relevant, but Stephen Archer has some information about the Umarex Fusion on his site’s blog. (I’m going to hold off posting the address since I’m not sure if that’s kosher. If Tom or Edith will OK it I’ll post a link to just the blog entry so people interested can compare his results with Tom’s.) According to him the Fusion is a development of the Xisico XS60C which was in turn a development of the QB 78. He mentioned in his initial review that the Xisico XS60C suffered from “seemingly unstoppable gas leaks and an automatic safety that did not work consistently.” He didn’t mention any gas leaks with his test rifle, though maybe he just got lucky. He also reported somewhere around 40 shots before he noticed power start dropping.

    As far as power levels go… Its worth remembering co2 is temperature sensitive. The only other review I’ve seen of this gun was done in the low 60s and produced velocities well below what the box claimed.

  20. What a coincidence I just received my Pyramyd AIR order for the Umarex Fusion along with the .22 Umarex Octane from FedEx this morning! So this blog was most surprising and thankful for me! I was reading this blog as it was delivered. After reading of the co2 loading problems I kind of just took it out of the box briefly. I liked what I seen, and the feel and the fit were nice, but i held off going any further until I read some more responses. I decided to mess with my new Umarex Octane. The instructions for the Fusion were kind of confusing to me. But they were exactely as B.B. had described. I did go on YouTube and found a video from a guy who showed how he loads the co2 cartridges into the Fusion. He starts by tightening the pressure relief screw all the way tightened and then still out of the gun he backs it out not just 3 full turns but 5? And then he screws the main part to the gun to puncture the seals. You can hear the huge rush of air escaping but after the main screw is finger tight he adjusts the pressure relief valve screw back a little more and it’s sealed? End of video? So I might play with this some tomorrow? But I look forward to all of the follow ups and info from all the other aspects of this gun. Also I’d love to hear anything mikeiniowa has to say or add to this blog? He seems to know about the fusion?

    • Greg
      What you explained from the video is kind of what I’m getting out of the instructions.

      Seems to me if you back the bleed screw all the way out you would just have a normal end cap like other CO2 guns only with a added o-ring for more sealing protection.

      Of course if they designed it right and use the right pieces and tolerances are correct.

      • Gunfun1, you are probably correct! As you’ll see my comment in part 2 of this blog not only did I turn the bleed screw out five full turns before even tightening the valve to the tube. But I had to back it out another few turns once the cartridges pierced. So the bleed screw now wobbles if you touch it? I didn’t take it all the way out because the manuel says that it could void the warranty. Actually as what B.B. discusses and mikeiniowa alluded to is that the piercing end of the valve assembly also can be screwed in and out and since the main guts of the valve are in that end maybe that’s what the warranty is about? Thanks gunfun1 for your input.

  21. B.B.

    Looks like the Fusion is turning out to be a winner. If the positive reports continue, it may be an early entry on my Christmas list.

    And now, to the age-old question: How long should I leave the two CO2 cartridges in the gun without damaging the seal?

    Often, I enjoy shooting just a couple of rounds, which will not fully exhaust the cartridges. This can get wasteful and expensive.

    I have a 2260 that I enjoy shooting in the warmer weather. Exhausting one, half-spent CO2 cartridge is not a problem, but the Fusion has two.

    I would be interested in your thoughts on the matter. As always, I greatly enjoy reading your reviews.

    Thanks, Mike

    • Mike,

      The CO2 will NEVER damage the seal. So it can stay charged all the time. Some guns have thin metal pipes in them that will bend under the pressure, but I doubt this one does. Its design doesn’t need them.

      But eventually the gun will leak down. It may take months and with some guns, years, but it will happen. The reason for removing the CO2 is safety. These guns can launch anything if they have pressure.


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    Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

    Free shipping may not be combined with a coupon unless stated otherwise.

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  • Shipping Time Frame

    We work hard to get all orders placed by 12 pm EST out the door within 24 hours on weekdays because we know how excited you are to receive your order. Weekends and holiday shipping times will vary.

    During busy holidays, we step our efforts to ship all orders as fast as possible, but you may experience an additional 1-2 day delay before your order ships. This may also happen if you change your order during processing.

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  • Shipping Restrictions

    It's important to know that due to state and local laws, there are certain restrictions for various products. It's up to you to research and comply with the laws in your state, county, and city. If you live in a state or city where air guns are treated as firearms you may be able to take advantage of our FFL special program.

    U.S. federal law requires that all airsoft guns are sold with a 1/4-inch blaze orange muzzle or an orange flash hider to avoid the guns being mistaken for firearms.

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  • Expert Service and Repair

    Get the most out of your equipment when you work with the expert technicians at Pyramyd AIR. With over 25 years of combined experience, we offer a range of comprehensive in-house services tailored to kickstart your next adventure.

    If you're picking up a new air gun, our team can test and tune the equipment before it leaves the warehouse. We can even set up an optic or other equipment so you can get out shooting without the hassle. For bowhunters, our certified master bow technicians provide services such as assembly, optics zeroing, and full equipment setup, which can maximize the potential of your purchase.

    By leveraging our expertise and precision, we ensure that your equipment is finely tuned to meet your specific needs and get you ready for your outdoor pursuits. So look out for our services when shopping for something new, and let our experts help you get the most from your outdoor adventures.

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  • Warranty Info

    Shop and purchase with confidence knowing that all of our air guns (except airsoft) are protected by a minimum 1-year manufacturer's warranty from the date of purchase unless otherwise noted on the product page.

    A warranty is provided by each manufacturer to ensure that your product is free of defect in both materials and workmanship.

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  • Exchanges / Refunds

    Didn't get what you wanted or have a problem? We understand that sometimes things aren't right and our team is serious about resolving these issues quickly. We can often help you fix small to medium issues over the phone or email.

    If you need to return an item please read our return policy.

    Learn About Returns

Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

Free shipping may not be combined with a coupon unless stated otherwise.

View Shipping Info

Text JOIN to 91256 and get $10 OFF Your Next $50+ Order!

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