What IS a gas ram airgun?

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 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.

    44 thoughts on “What IS a gas ram airgun?

    1. I HAVE A BEEMEN RX-2 IN .20 CAL. AND WOULD LIKE TO GET A LITTLE MORE POWER FROM IT. I,VE HEARD THAT BEEMAN OFFERS A NITRUS SUPER CHARGE FOR THE GAS BAG. DO YOU KNOW IF THIS CAN BE DONE AND IS IT WORTHWILE. WHATS THE DIFFERENCE BETWEEN THE CROW MAG. AND RX-2.


    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.

      B.B.


    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.




    4. THE CROSMAN PREMIER PELLET SHOOTS WELL IN MY RX-2 AND IS A HEAVY PELLET IN .20 CAL.AT 14.2 GRS.
      I WANTED TO STEP THE VELOCITY OF THIS GUN UP A BIT SO I’VE BEEN TRYING THE BEEMAN KODIAK AT 13.3.
      WHAT A PLESENT SUPRISE. THE ACCURACY SEEMS BETTER THAN THE CROSMAN AND THEY GET TO 20YDS ALOT FASTER. MY NEXT STEP WILL BE A TEST AT 50YDS. I LIKE THE KODIAK IF IT WILL HOLD ITS OWN OUT TO 50.


    5. D. Smedley,

      Yes, Kodiaks are often a pleasant surprise. You might also try cleaning your barrel with some JB Non-Embedding Bore Compound. I will describe how to do it next week.

      B.B.




    6. 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 ?


    7. There is no caliber distinction for a gas spring. It’s made for a gun only. Any airgun that is changed from .177 to .22 will gain about 20 percent in power because .22 in more efficient that .177.

      B.B.



    8. 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!


    9. 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.

      Sorry,

      B.B.




    10. 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


    11. 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.

      B.B.


    12. 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!





    13. 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?

      Thanks.
      Jasper



    14. 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:

      http://www.pyramydair.com/blog

      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


    15. 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.

      B.B.



    16. 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.




    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.

      Cheers,

      Bobby

      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:

      http://www.pyramydair.com/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,

      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.

      B.B.



    24. 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


    25. 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:

      http://www.pyramydair.com/s/a/Air_Venturi_Gas_Spring_Conversion_Fits_Webley_Patriot/2102#productDescription

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

      http://www.airgunwerks.com

      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




    26. 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.

      B.B.


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