Gamo Extreme CO2 – Part 1

by B.B. Pelletier

As I go through all the airguns on hand and get ready to report on new ones, you readers are generally ahead of me, urging me to test this one and that one. I thought I was going to surprise you with the Gamo Extreme CO2, but just yesterday, Dallas from Australia asked for it. How strange, because it was slated for today a week ago.

How many of you remember that Gamo had a CO2 rifle back in the 1990s? The G1200 was a pump-action (slide action, actually) repeater powered by 12-gram CO2 cartridges. The Blue Book of Airguns has precious little information on that rifle, but I was around when it was new. I don’t know how well it sold here in the U.S., but the advertised velocity in .177 was 560 f.p.s., which is pretty reasonable. I would expect a velocity of not above 620 f.p.s. from a hot .177 CO2 rifle with any size cartridge or reservoir. But the Extreme CO2 is not a .177. It’s a .22! So I find Gamo’s claim of 700 f.p.s. to be extremely interesting. I will be certain to explore it for you.

Of course, it’s summer now and CO2 guns are summer guns, so this is an appropriate rifle to test and use. The Extreme CO2 uses an 88-gram cartridge that gives the rifle the potential for a great number of shots. They will not be more powerful than those from a 12-gram cartridge, of course, because the size of the container has no bearing on the pressure of the gas. But this is a plinking gun and more gas is very desirable for lots of continuous shooting.


This “thousand-word” picture shows where the 88-gram gas cartridge goes, which is under the sliding forearm. The long, sloped rear sight is also visible.

This is a repeater, too, and not just a repeater–it’s a slide-action repeater or what is best known in the firearms world as a pump gun. I use that term with care because I find that it confuses new airgunners, who equate the word pump with a multi-pump pneumatic. The Extreme CO2 runs on CO2, only. The term pump in this case refers to how the circular clip is advanced and how the rifle is cocked. The synthetic forearm slides straight backward, advancing the clip and cocking the hammer. Then it returns forward again in preparation for the shot. Once you get accustomed to the movement of the forearm, a pump gun is almost as fast to shoot as a semiautomatic.

Okay, 700 f.p.s. and .22 caliber. What does that tell you about the sound? This rifle will be LOUD, make no mistake. It has to be, with that volume of gas being exhausted from the muzzle. Even if it doesn’t reach 700, it’s still clear that Gamo intends for this to be a powerful rifle–and power in a gas gun means noise, as a rule.

This is a 10-shot repeater and comes with two rotary clips. To load, you have to pull the forearm back, then pull back on a locking lever to unlock the clip.

The forearm removes by pressing two buttons–one on either side, and pulling it straight forward and off the gun. It must be removed to install an 88-gram CO2 cartridge. Both the forearm and the piece it attaches to that remains on the gun are made of plastic. I will watch them both for signs of stress, because they operate the action. The safety is a crossblock type that runs through the bottom forward part of the triggerguard.

Most of what you touch on the gun–butt, forearm, barrel casing–is plastic. But the receiver is annodized aluminum with a black finish over a heavily bead-blasted surface. Therefore, the Extreme CO2 is not a light airgun. It is both large and heavy–at least for a CO2 rifle. The length of 43.3″ overall and weight of 7.7 lbs. don’t convey the sense of largeness felt when the rifle is in your hands. The CO2 cartridge and scope that come with the gun boost the weight to over 9 lbs.

The stock is fully ambidextrous, and so, of course, is the pump action. Lefties should really enjoy this one. The synthetic stock is hollow, so many of you will want to fill it with foam to deaden any vibration.

The open sights are quite unique. The front is a red fiberoptic bead, which is not uncommon, but the rear is a long, sloped ramp with a yellow arrow to align with the front. It looks like it will be quick to acquire. Of course the scope that comes with the rifle will probably be mounted in the preponderance of cases. It’s a 3-9×40 scope that appears clear enough after the first examination. It comes with a one-piece mount already on the scope, so all you have to do is clamp it to the receiver dovetail.


The rear sight is a long, gentle slope. The yellow arrow points to the red bead front sight when you sight over the receiver. It looks like a landing pattern when you see it in person!

This has been a boom year for new airguns, and this would appear to be one more to add to the mix. Of course, we have to test it to be sure, but I like this rifle already–just from the feel.

49 thoughts on “Gamo Extreme CO2 – Part 1”

  1. BB – the sights sure looks non-adjustable to me. Am I missing something? And the front sight FO assembly is unhooded. It looks to be the same as the FO assembly used on a slew of other Gamo rifles, and has proven itself to be rather delicate. Gamo had started putting a hood over those front sights, and offering a hood that could be fitted to earlier models that didn't have it. But this one appears not to have even the slots for mounting one…

  2. B.B.,

    This is a gun I didn't know about until I saw Dallas from Australia's question. Looked the gun up on PA's site and got confused pump gun and CO2??? What do they mean by that? I think the term slide action would stop alot of confusion? Should be a great trigger cause it won't be tasked with advancing the clip or cocking the gun.

    I'll be curious on how well the gun shoots using the standard sights.

    Mr B.

  3. Pyramyd Air,

    In shopping for guns I'm disappointed that the "Latest Buzz" doesn't link to the articles that B.B. has written.

    In the example of the Hammerli Pneuma the latest buzz link takes me to a short, incomplete article written by Jim Chapman and doesn't mention anything about the detailed 3 part series that B.B. has completed on this air rifle. The Evanix Blizzard doesn't have a link to the latest buzz even though B.B. has started an indepth report on this gun as well.

    It is very helpful for shoppers to be able to link directly to this invaluable information, while we're on your site looking at a particular gun, when we're trying to make an informed decision about our next purchase.


  4. No, BB, you didn't say anything about the sights being adjustable. Just seems odd, to me, anyway, that air rifle sights wouldn't be. Can't think of any other rifle like that…

  5. BB,
    Looks like a good "Scout Rifle" as Jeff Cooper would say, I mean the bright sights and carbine size. Too bad I will never buy another gamo.
    Shadow Express dude

  6. B.B.

    Interesting. I was all set to promote the Ruger 10/22 to the status of icon as the pre-eminent .22. With forty years production, 5.7 million copies sold, an enormous aftermarket industry, an innovative detachable magazine design, dominance of competition and possibly the highest current popularity of its class, the case seemed pretty strong. But I see there is a whole earlier era of .22 designs. I would think for the plinking that most .22s are used for that the slide action would be ideal.


  7. Matt,

    That was how it was when I was growing up. The Winchester 61 was the king, but the Winchester 1890 and 1906 were good guns, too. The cool thing about the two older ones was you could hold the trigger down and work the pump as fast as you could and the rifle fed and fired that fast. I did that until the day a cartridge burst outside the receiver and taught me some caution.

    Remington had their model 12 and Stevens made a funny one they called the "Visible Loader that actually loaded the cartridge from outside the gun. The mechanism pushed it back outside the receiver and then back inside.

    I loved my pump guns!


  8. There was a gentleman at the Union Co. (NJ) Pistol range shooting a Model 61 several weeks ago. What a lovely looking rifle. He felt these had to be used and not kept in closets.

  9. BB

    A friend of mine picked up a Winchester model 78G .177 co2 pistol the other day. Can you tell me anything about that model. It seems to be very well made and if I looked at it correctly has 2 power settings.

  10. Matt,
    There's been so many good .22's over the last century or so that it seems a shame to make the 10/22 iconic:). I initially liked it in stock form, but the aftermarket hoopla and many amazingly unfit configurations put together by enthusiasts has just about made me sick.

    Regarding your question the other day, most of my optics experience comes from astronomy and astrophotography, where I've used and even built telescopes and astrographs and couldn't help but learn a few basics:). Riflescopes are fairly interesting devices, because they have several conflicting requirements and by definition must stand up to rough handling. The most infuriating shortcomings of riflescopes, for me at least, are mechanical and not optical, although I often see people praise or criticize a scope's image quality as if it were supposed to be as good as a Takahashi or Astrophysics, with little understanding of how many compromises are essential just to make it work in a package small enough to carry around on a rifle. I think that if people better understood some of the principles involved, they could prioritize their requirements and make happier choices.

  11. 78G,

    Your friend's pistol is actually made by Smith & Wesson. It's a copy of their model 41 .22 rimfire target pistol.

    The early models had an adjustable trigger, but that was discontinued. And if you sent your pistol to S&W for repairs, they removed the adjustable trigger, I have been told.

    The gun has a single power setting, inlike the Crosman Mark I and II.


  12. 78G…….
    I have one in .22 cal.
    It has an adjustable trigger, Can be cocked half way or all the way for two instantly available power settings, and also can be adjusted with a screw right under the muzzle for different power levels.


  13. I have a 78G that I bought back in the 70's. Mine is .22 cal. They also made a model 79G which was .177. The Blue Book of Handguns has the model number and caliber numbers reversed. As BB said, the trigger isn't adjustable but the power setting is infinitely adjustable, at least on mine. The screw that's just under the barrel adjusts tension on a spring which pushes a striker against the CO2 release valve. Dte of manufacture was from 1971 to 1980. I think this pistol is more accurate than my Gamo Extreme. It's a neat pistol and I prize it greatly.

  14. Fred….
    The trigger on mine is adjustable on the second stage by a setscrew on what appears to be the end of the sear that is showing just in front of the trigger.


  15. Thanks everyone for your input on the 78g I've been airgunning for 30 years and have more fun with it now than ever. I'll let my buddy know what he has. Just one more thing does anyone on this blog live in the Kansas city area. I've a couple of buddies who get together every weekend and shoot. Would be nice to meet a few more people with the same hobby.

  16. Fred….
    When cocking , there are two clicks. The first is about halfway through the cocking stroke and the second is at full stroke. It cocks at either position.
    The second position gives the hammer more spring loading and travel .

    Two different positions….two different power levels.


  17. BB, Wayne, Anyone
    Off topic for a bit.
    Does anyone out there have any experience with both the AA-S410 and the Weihrauch HW-100?
    Both are in the thousand dollar range which, for many of us, is a lot of money, for any gun.
    Although each is an excellent gun with equally excellent workmanship, I was just wondering about the pros and cons of each.
    That is if either has any cons.
    It seems the owners of each swears by them as the best gun they have ever owned.
    P.S. I know the S410 has adjustable power, does the HW-100? Nothing I have read indicates that it does.
    Thanks to all.

  18. Fred….
    I bought mine in the early 70's. Brand new frome some store….don't remember where.
    If I remember right, if i adjust the trigger too far it will not cock.
    Seals in the piercing assembly went bad somewhere along the line. Got replacements from a guy down in texas.
    It will leak down after a while if I leave a cart in it.
    Good shooter.
    Caught a bunch of crap from my room mate for drinking beer and shooting flies off the junk sofas with it while listening to some good rock and roll.
    Tore up the fabric and left guts, wings, and legs all over the place.


  19. Anonymous,

    Re: AA S410 vs. HW 100

    I don't have experience with both but my choice of the first pcp to purchase boiled down to these two guns after much research and consternation.

    It took alot of time for me to "tune out the noise" of those individuals that either own on or the other gun since they champion their choice without experience with the other gun. I had many conversations with individuals that convinced me that they owned or had shot both the AA S410 and HW100.

    Here's what it boiled down to in my research:

    AA S410 SL .22 – Lightweight, shrouded, accurate, powerful (32fpe) (Hunting)

    HW100T .177 – heavy, very loud, acurate, less powerful and very important REGULATED. More suitable for use in FT.

    It really depends what you want it for.

    I wanted to shoot informal target at distances ranging from 20 yards to 100 yards and use it for hunting.

    My choice was the AA S410 and I am very happy with the choice.


  20. Tiru,

    I can't comment on the HW100.. but Kevin laid it out pretty well, I think..

    My AAs410 is a .177 and it gets about 25 foot pounds on high power with 10.6 kodiak (1030 fps)

    I'm very, very happy with mine.. so much so my handle on the yellow is "S410happy"..

    Ashland Air Rifle Range

  21. Kevin, Wayne
    Thanks for the feedback. I was leaning toward 410, but just wanted to be sure. Another month or two and I'll be calling PA.

    Thanks Guys

  22. 78G,

    Well, you just defined Friday's blog! I searched for a report to link you to and found nothing. I know I've shown a photo of the 78G in the past, but it appears that I haven't actually tested one yet.

    I'm grateful to Twotalon for reporting the two power levels his gun has, because years ago I reported the same thing in The Airgun Letter and was criticized because nobody had one like that. Well, at one time I owned an early model with the adjustable trigger that did have two power levels.

    My current example has only one power level, which is the norm for the type. They all have a power adjustment screw.


    • LR,

      Welcome to the blog.

      The front sight on this airgun is a red fiberoptic bead, and that would look like a red plastic tube at the front of the gun. If your gun doesn’t have one, you need to contact your dealer and ask him about it.


    • Pardon the interruption, but which particular “Gamo Extreme”?

      The PA web site seems to indicate that the “Gamo Extreme CO2” (the version reviewed on this page) has been discontinued for some time.

      The Gamo Hunter Extreme SE does not come with any open sights, you must put a scope on it. Same goes for the Gamo Bull Whisper Extreme — no open sights. Those are the only “Extreme” models listed by PA.

  23. Thanks fellas.
    It does have the yellow arrow at the rear and looks like it would take a front sight it has adjustment screws on the front of the barrel to adjust up and down.

    • LR,

      It does sound like you are missing the front sight blade.

      I am guessing that you did not buy this gun from Pyramyd Air. If you had, they would have taken care of the problem for you. Can you work with your dealer to take care of it?

      Since the gun isn’t being sold anymore I don’t know if Gamo USA has any parts, but you might call them if your dealers can’t help you.


  24. Thanks BB & Wulfman
    This is my first blog. You blokes are bloody legends.
    I brought the gun from Queensland & had it sent to NW Australia Dampier. My mates old man Nutsy is a tool & dye maker is knocking one out for me. Down Under style.
    Cheers LR

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