Home Blog  
Education / Training What is a gas ram air rifle?

What is a gas ram air rifle?

by B.B. Pelletier

This post is a direct response to a comment that came in last week:

  • Now for the 64 dollar question? Which Weihrauch model would you choose to purchase if you eliminate price as a factor and exclude pneumatic? I don’t know what a gas ram system is, so you may include these models if one doesn’t have to purchase pumps, compressors or CO2.

A gas ram airgun is a spring gun…without a spring!
A gas ram airgun is a spring-piston gun in which the coiled steel mainspring is replaced with a sealed “gas spring” unit. Instead of the coiled spring pushing the piston, compressed gas does the job. “Gas ram” is just one name for this powerplant. It’s also called a gas strut and a gas spring, which I prefer because it is more descriptive of the unit.

You find gas springs in many mechanical things these days. Cars are probably the most familiar. Anyone who owns a minivan has seen a gas spring unit push the deck up when it’s opened. Gas spring units have all but replaced coiled steel springs.

gas ram air rifle

Gas spring advantages
There are several advantages to gas springs over steel. Here are a few:

1. They last longer. Gas springs last for decades, while steel springs wear out in the same timeframe. Gas springs seldom leak, so it doesn’t matter whether they are under tension or not – they still retain all their power. Steel springs fatigue over time if they’re under tension. You can leave a gas spring gun cocked for weeks, and it will not lose any power.

2. They are lighter. A gas spring unit, which includes the piston, will shave off close to a pound of the rifle’s weight.

3. They are faster. Gas springs react faster than coiled steel, so they get the pellet out the muzzle quicker. They tend to be more powerful than equivalent guns with steel springs, but that can easily be adjusted with piston diameter and stroke length.

Gas spring disadvantages
Very few disadvantages, but you should know what they are before you buy a gas spring airgun:

1. They are harder to cock. For muzzle energy equal to a conventional coiled steel spring, a gas spring can tack on another 50 percent to the cocking effort.

2. They have a harsher firing behavior. They don’t vibrate like steel springs, but the jolt when they fire is quick, sharp and objectionable to some shooters. They also tend to be harder on some scopes.

Limited availability
Ten years ago, there were real choices in gas spring airguns. Theoben, the British company that made them popular, was selling a large line through Beeman, plus some people were importing the guns straight from England. The Weihrauch company put a Theoben gas spring into the Beeman RX, which is the RX-2 today.

RWS imported the RA800, which was a wonderful mid-level breakbarrel. Then, Vortex started selling gas spring units so shooters could convert their Weihrauch and Webley guns from steel springs. They were available for the R1, HW77, Beeman Kodiak, TX 200 and a few others. Today, only the Beeman RX-2 is still available in the U.S.

Is a gas spring a good powerplant? Absolutely! Is it the best? That’s hard to say. Read the advantages and disadvantages and decide for yourself.

59 thoughts on “What is a gas ram air rifle?”


  2. D. Smedley,

    I don’t know what gas Beeman uses for their “Super Gas” job today, but it used to be Nitrogen. It kept the gas cylinder dry, and helped prevent rust.

    They say it makes cocking and firing smoother, but they make no claim for greater power.

    Your .20 caliber can probably just reach 20 foot pounds with the heaviest pellets. A Crow Magnum in .20 caliber will hit 25 foot pounds with the heaviest pellets, so there is the difference. Both guns have a gas spring made by Theoben, but the RX-2 is made by Weihrauch.


        • Thank you B.B.
          Can you tell me more clearly? What’s I need to made myself? Gas spring? Piston? Or…?
          My country was forbid using any gun, include airgun, sport gun… and I want to buy spares.
          Thank you very much.

          • Linhtote,

            I would forget trying to make a gas spring. That would take a master machinist. I would look for another coiled steel spring for your rifle. You can cut them down if they are too long.

            As for a piston seal, you can make a leather one easily from an old belt.

            Does your rifle work now?


          • Lintote,

            If I may ask?,… What Country are you from? It is always interesting to hear from other people in other parts of the world. I enjoy the different points of view and perspectives.

            Of most interest is why you are seeking air gun parts in a country where you say that air guns are illegal? Can you do that ok without getting into any trouble?

            Air guns are nice. It is sad to see them restricted in any way.

            By the way,… welcome to the blog! 🙂

              • Linhtote,

                You could possibly order a replacement spring from Alibaba. There is a company listed there willing to sell one spring at a time. Compared to most that will only sell in lots of 500-1000.

                Why would you want to convert it into a gas ram?


              • Linhtote,

                Thank you for the reply. That is too bad that even a simple bb gun or pellet gun is prohibited. Good luck on getting what you want. Be careful and do not get yourself into any trouble.

                Keep us posted and check back in.

  3. I learned much from this post. In your opinion, what is the best gasram airgun for use in field target competition? I prefer to use the .22 caliber as I use my airgun for occasional rat control.


  5. One more question about gas springs : it seems that if you fit your .22 airgun with a gas spring that is made for a .177 it will increase the power of your .22 rifle. This is written on the webside of Theoben.IS IT TRUE ?

  6. I just purchased an RX-2 from Pyramid and all I have to say is “WOW”! My previous experiences with air rifles included my childhood Red Ryder, my Dad’s Blue Streak, and a Gamo 440. I got the RX 2 in .22 and it really packs a punch! I especially like the feel of the trigger.

    Now that I’m finished praising this rifle, there are a few things I want to bring up…

    1st- I have no problem handling this 10 lb. beast, however I would like to know if there are any aftermarket stocks for this rifle that might lighten it up a bit. I mostly us it for small game hunting (california ground squirels, and jack rabbits), and after a few hours I find myself using something to rest it on. If there aren’t any lighter stocks, would “skeletonizing” it take off much weight? If I go this route how much is safe to take off without jepordizing the strength of this rifle?

    2nd- (This is more of a statement, than a question) I purchased a leapers Bug Buster 2 scope for this rifle and like it a lot. However due to the short length of this scope, I find myself having to arch my neck forward to see clearly through it. I have it mounted as far back as possible. This doesn’t bother me if I’m resting the rifle on something, however it is literally “a pain in the neck” if I shoot while standing. I just ordered a full size Leapers 3-9×50 AO Mil-Dot Scope to fix this problem. The bug buster is going on my shorter, and much lighter, Gamo 440. I suggest that anyone who is looking to purchase a scope for this rifle, get a full size scope instead of a mini. Especially if you have a short neck like myself! LOL

    Well, there’s my 2 cents. Also, thanks for all of the great info BB! I’ve learned quite a bit by browsing through your blog!

  7. RX-2 owner,

    I wouldn’t skeletonize your rifle’s stock if I were you. The harshness of the gas spring recoil could crack a weakened stock. I don’t know of any way of lightening the RX-2.

    Nice comment on the Bug Buster 2. Since I use it more on PCPs, I had not experienced your problem.



  8. Interested in buying a gas spring airgun. Have looked at RWS RX-2 and Theoben Crow Magnum. Have you a recommendation between these two? Any others you especially like? Intent is to maximize accuracy and power at 25-50 meter range. Considering .20, .22, and
    .25 calibers. Your thoughts on caliber? What scopes will hold up to the recoil in gas spring airguns? Thanks. Look forward to hearing from you. // Sam

  9. Samiam,

    I’ve owned and tested the Beeman Crow Magnum (Theoben Eliminator) very extensively. I had one in .25 caliber that wasn’t very accurate, and another in .20 caliber (same rifle, different barrel) that was much better. My choice of calibers is .22.

    I haven’t tested an RX2, but a lot of people write that they love theirs, so it must be pretty good.

    Any good scope these days will stand up to a gas spring. I had a Leupold Vary X II, which isn’t rated for airguns and it didn’t suffer.


  10. I have the Weihrauch version of this rifle, (HW-90), that I ordered from Pyramid a few years ago. (I do NOT see this on their website any more though.) This rifle remains one of my prized possessions. It truly is a work of art. The attention to detail is evident throughout.

    The recoil on this rifle is pronounced, but very manageable once you become accustomed to it. This air gun fires much more like a traditional firearm in this respect. Note that I used a scope off of my .177 Beeman air rifle, and the recoil completely SHATTERED the lens in the scope. I have since invested in a more robust scope, complete with a one piece mount AND a stop. No complaints now. The rifle is dead on accurate. At 10 yards, I can use target “toys” designed for firearms. I have the .22 version, and use Beeman Kodiaks or Crow Magnums. The power is definitely there! I still occassionally use this for pest control, but the pigeons don’t seem to hang out at my house any more.

    The rifle IS heavy, but I installed a sling on it, which makes it no problem to carry for extended periods. Cocking effort is substantial, but I am a big guy, so it’s not a problem for me. I also installed a muzzle break, which provides for an extra couple of inches of leverage, as well as helping a bit with the report of firing. This rifle is on the louder side.

    Receiver is marked with the Weihrauch information and also prminently marked Theoben. Pretty cool.

    This is a really nice rifle, and I like mine alot!

  11. Hi,

    Can anyone tell me if Theoben/Weirauch or Air Ventury gassprings do have an internal damping system and / or what the extension speed of the rod is?

    I have a Gamo 1250 .22 which I would like to upgrade with a gasram.

    For this type there are no aftermarket gasrams available.
    Now, after some research I have been told that gasrams in airguns
    are not the same as used in ie. Cars.

    Standard gasrams/gassprings as available in several (online stores) and do have a maximum extension speed of 300 mm/second.
    Also, the are included with an internal damping system that slows down the extension speed till about the 300 mm/second.

    Any expert here who know’s the technical specs from gasrams as used in airguns? For example:Which extension speed of the rod has a Theoben gasram?


  12. I have a good one for you…
    Why wont a Gas Ram work In a Crosman Storm XT?
    Both Crosman and Pyramid Said No Way
    However they didn't say why
    Is there a gas ram that would Work in The Storm XT and Rifles like it?

  13. DHPP,

    I don't know exactly why either but typically there is a problem with the size of the gas strut (either too wide or too long) or the trigger mechanism and the catch on the ram are not compatible.

    You should realize that you are posting on a 5 year old blog and very few of us, other than several volunteers, monitor these comments. For greater exposure and comments (and perhaps the exact reason why a gas ram won't fit in either of these rifles), post your comment on the current blog. It can be found here:


    The most current blog will always be on top. Be careful as there will be a number of blogs here. Scroll down to the end of the first blog and you'll see the "comments" link. We welcome off-topic comments.

    Welcome to the airgun blog. We look forward to your continued visits, comments and questions.

    Fred PRoNJ

  14. DHPP,

    Fred gave you a good technical answer. I will give you the business answer.

    With all the new Benjamin Nitro Piston guns coming out, why would they (Pyramyd AIR or Crosman) invest the money to create a new gas piston that converts a model selling in the budget class? Buyers of these rifles typically do not spend the same money or greater to modify them.


  15. DHPP, I'd be very surprised if Item#:AV-G748119[PY-A-2103] – the Gas Ram for Gamo's – wouldn't fit the Storm. The Quest variants are close copies of the Gamo, and (given the way Gamo doesn't sell spare parts) a LOT of Gamo's wound up with Quest springs, seals, and even triggers in them.

  16. Too right
    To answer the Money Question?
    Not Every one these days can afford a new gun
    I for one can not
    So if i cant put a Nitro or a venturi Gas ram in my storm how about a Spring that has more punch?
    and not likely to break after 6 months of use?

  17. don't have a chronograph
    all i know is after a while a month or so the squirrels i shot got up and took off
    this was at 70 foot away
    the box says 100 fps i think the reviews on pyramid said the most they got was in the 5's or 6's
    don't get me wrong this rifle has potential i just want to make it better!

  18. DHPP, A Storm XT should be advertised at 1000fps, not 100. That powerplant should be able to generate at least 860-870fps (some will do more) in .177 with a pellet like the Crosman Premier. If it's down in the 500-600 range there is something seriously wrong with it.

    Having the squirrels run away means nothing, it depends on where you hit them. You need some way of better quantifying the gun's performance before you can really tell if it needs help.

    That's not to say that the gun might not be up to snuff. I've seen a couple of these with rough tubes that abraid the seals, wearing them down so that the power goes into the toilet. Guns like that need a good honing and a new piston seal. It's also quite possible that the spring has broken.

  19. DHPP,

    I'll second Vince's comment regarding squirrels. They're tough as nails with an amazing will to live.

    I've personally shot one with a fully functioning Ruger AirHawk only to see it run off a few minutes later. For the record, I do have a chrony and that gun goes 16 fpe with the pellets used during that hunt. The squirrel hit the ground 'dead' only to pop back up 10 minutes later and run off.

    The following day, I came back with my Beeman R7 and got him with a head shot. Later, during cleaning, I found that the AirHawk's shot had passed through the muscle of his shoulders and neck leaving a massive wound channel, yet it didn't kill him. The shock apparently paralyzed him for the 10 minutes he lay on the ground until it wore off. The next day, he was frolicking around as if nothing happened at all.

    Tough buggers! It's why I enjoy hunting them so much.



    BTW, chrony's can be had used for $50-$60 or so on the various airgun classified sites. They're a much better investment of your airgun funds than trying to shoehorn a gas spring into your Quest. My 2 cents.

  20. you guys have been a lot of help with this project
    The storm i am about to repair has a busted spring and the seal is chipped round the edges
    as for mine? after replacing the seal and spring i have not had a problem i have 9 doves 6 squirrels and countless grackles to prove it
    i plan to upgrade to the varmint hunter scope on it and then go after rabbits in north Florida
    I noticed gamo has a new hot rod out its called the rocket
    wonder if the nitro piston will work in it
    Again thanks for the help

  21. Hi, I would like to know if the gas rams loose gas pressure in time.
    Is there any way to charge them with gas again?

    Is there any way to adjust the inner gas pressure if this one affects the accuracy or speed of pellet?

  22. Richard HN,

    The majority of gas rams are sealed units meaning you can't add gas to them if they lose pressure. However, the early Theoben gas rams did allow for it, but I don't think that they do any more.

    BTW, you have posted your question on an older blog. Not many people in our airgun community will be reading hundreds of old blogs on a daily basis. For the fastest and most plentiful responses from a variety of viewpoints, post your question on the current day's blog:


    Do not be concerned about posting questions that are not about the current day's topic, as that is the place to go, and you will not be scolded or treated badly as you may in some places for posting "off topic".

    Feel free to post any observations, experiences or suggestions regarding the relevant topic on older blogs. People new to this resource will most likely be directed to this blog as a result of a Bing or Google search and will be directed to the relevant topic on an old blog, and your comments will be more likely to reach them there. You can post these same experiences on the current day's blog as well as the day of the relevant topic, if you want. Also keep in mind that the blogger software only display's the first 200 posts initially, so if you post to a blog that has that many or more posts already, most people will never see it because there is no "Next" button at the bottom of the page and it is easy to think that the last post shown is the last post.

  23. Richard HN,

    Here's the link to B.B.'s discussion of the early Theoben gas rams and how they were adjusted (and the problems this adjustability caused)


  24. Richard HN,

    Gas springs are not supposed to lose pressure in many years of service. I have a gas spring for my Beeman R1 that is about 12 years old and it hasn't lost any power. If they lose pressure, it will typically happen all at once.

    Look at the gas springs in your family car. They remain pressurized for a long time and stay fully compressed most of the time yet they continue to work year in and year out.


  25. Filflo6,

    the gas spring that Pyramydair sells is supposedly only for Gamo Whisper air rifle series such as the Hunter Sport, Varmint Hunter, Big Cat & Viper Shadow Express. They do sell this for customer installation. However, if you told them you wanted to try to install it on another rifle it's not made for, they would refuse to sell it to you.

    We'll check a little further and get back to you. What rifle did you intend to use the gas spring or ram for?

    Fred PRoNJ

  26. Filflo6,

    I have been told that Pyramydair will NOT sell a gas spring from Crosman for self installation by a customer. However, their Air Venturi spring is apparently available for self installation:


    You might consider it if it will fit your rifle. One other source is


    However, I don't know if the owner, Dave Slade, will sell these springs without installing them himself. You'll need to contact him.

    Good luck.

    Fred PRoNJ

  27. The Theoben guns use gas springs, as do the guns that have the Gamo Inert Gas Technology.

    That's why I use the term gas spring, which is the term used by industry. Gas Ram, Gas Strut and other slang terms just confuse people and keep me answering questions.


  28. I know this is an older blog but i cant find a newer one on this subject.Q.Ive shot 8,000 pellets threw my Ruger Yukon in 2 months,all is well,very happy w/it w/ the sight mods ive made. Has any one any idea how long it will last? I cant find any manufactuer stating any thing but the obvious advantages of gas rams,it seems to stop there. surely im not the only guy that shoots a gas ram this much. Is it spose to die soon? should i be thinking of a new rifle? I dont think Uma can replace at reasonable price. Mine deff aint under warranty. I didnt realize id be shooting this much being disabled but i have fallen in love w/this thing & love the exercise on my shoulders.
    As a X machinist i understand..run it till it breaks..as ive told many a customer.
    But has any one ever commented on how many shots they got? ive read alot about it all but cant find this top secrete info (haha)I find the generic..last longer,either works or it dont.
    I cant be the only guy stuck inside in the winter having a gas ram marathon…i say this laughingly. but will i have any gun left w/spring comes back around. Cause i just got 2,000 more pellets.
    Im wondering if i should leave it be while its perfect and get another one to start a marathon on.
    And if i am the only guy? guess ill let ya’ll know when it gives out so youll have this info to pass around. im goin to set a record if they aint one yet.

    • Rafer,

      Welcome to the blog.

      You don’t have to post your comments to a report with the same topic. We go off topic all the time. So come to the current blog page in the future.


      I can’t help you with longevity of a gas spring, except to say that industry uses them instead of coiled steel springs because they do last through many more duty cycles. I have one that’s 15 years old. It hasn’t got the number of shots yours has, but it still performs like new.


  29. How about a magnetic ram airgun?

    There is a company called “Polymagnet” (http://www.polymagnet.com/ & https://www.youtube.com/watch?v=drD416THU7Y) that develops programmable magnetic field materials. These polymagnets as they call them can have amazing properties, for example strongly repealing each other but reversing repulsion into attraction when getting into the right distance from each other.

    A Correlated Magnetics Spring Polymagnet as they call it would be a very interesting technology in the field of airguns, see https://www.youtube.com/watch?v=J8w6gwSm_ak

    This in my mind could be the next evolution in break barrel airguns, from nitro pistons to magnetic pistons (improvements in friction, recoil etc)

      • Typical magnets wouldn’t be applicable in any sort of airgun application I can think of but with this company’s programmable magnetic field materials, I believe it’s a whole different story. I was going through some of their applications videos and a number of ideas popped up into my head about a frictionless, 100% truly vibration + maintenance free, reliable & easy to cock airgun piston…

        It would be very interesting if you shared this idea with any contacts you may have within the airguns industry (Crosman or whoever). I am sure that their R&D or engineering teams could come up with much more functional & complete ideas on this than my brainstorming.

        Who knows, sometimes a stupid or weird idea is all it takes for a major breakthrough…

Leave a Comment

Buy With Confidence

  • Free Shipping

    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

  • 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.

    View Shipping Times

  • 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.

    View Shipping Restrictions

  • Expert Service and Repair

    We have a team of expert technicians and a complete repair shop that are able to service a large variety of brands/models of airguns. Additionally, we are a factory-authorized repair/warranty station for popular brands such as Air Arms, Air Venturi, Crosman, Diana, Seneca, and Weihrauch airguns.

    Our experts also offer exclusive 10-for-$10 Test and 20-for-$20 Service, which evaluates your air gun prior to leaving our warehouse. You'll be able to add these services as you place your order.

    View Service Info

  • 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.

    View Warranty Details

  • 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!

* By providing your number above, you agree to receive recurring autodialed marketing text msgs (e.g. cart reminders) to the mobile number used at opt-in from Pyramyd AIR on 91256. Reply with birthday MM/DD/YYYY to verify legal age of 18+ in order to receive texts. Consent is not a condition of purchase. Msg frequency may vary. Msg & data rates may apply. Reply HELP for help and STOP to cancel. See Terms and Conditions & Privacy Policy.