Home Blog  
Education / Training How do airgun manufacturers come up with the maximum fill pressure for their precharged airguns?

How do airgun manufacturers come up with the maximum fill pressure for their precharged airguns?

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

Today’s report came from a question asked by blog reader GunFun1:

“How do airgun manufacturers come up with the maximum fill pressure for their precharged airguns?”

He went on to say:

“I guess it is safety related and to protect the o-rings also. And if the gun isn’t adjustable for the striker and spring I guess they test to see if the gun will get valve lock or something? Or is for the fact that most hand pumps won’t go too much above the 3000 psi fill level with the exception of a few brands?”

The report
What I am about to tell you has been collected from dozens of meetings and tours through airgun companies. I’ve been in the engineering departments, talked to the development engineers, and seen the CAD systems and the prototypes they work on. I’ve also had long discussions with smaller airgun builders like Dennis Quackenbush and Gary Barnes. I know how they approach this problem. So, I can tell you what I’ve seen. That’s not the same as a full disclosure report, but I don’t think you’re going to get that anywhere.

Doing what works is Job One
Airgun companies don’t “come up with” the maximum fill pressure at all. At least they don’t do it as an initial calculated engineering step. It’s not a primary goal, except in a few instances I’ll mention. Instead, what they try to do is design and then build a precharged airgun that works. One that shoots pellets out the muzzle. That’s always the first objective.

In coming up with “what works,” each company has something definite in mind. One company may want to build a 10-meter target rifle that fires an 8-grain .177 pellet at 575 f.p.s. for at least 120 shots from a fill, and they don’t want the velocity to vary by as much as 10 feet per second throughout the entire shot string. There are several paths available to them — things like pressure regulators, balanced valves and so on.

Another company wants their gun to propel a 30-grain .22-caliber pellet at 1,000 f.p.s. They are making a hunting rifle, and their first goal is to get the power they are seeking. After they get it, they’ll then look into getting the most number of shots from a single fill.

A third company wants to build a rifle that gets a lot of shots in the 25 foot-pound region. Their primary goal is the number of shots they can get at around 25 foot-pounds.

Where does fill pressure fit in?
In all of this, the fill pressure hasn’t been mentioned, but it has been in the backs of all the minds working on the primary goals. For example, most airgun manufacturers know that shooters in the United States have easy access to air at pressures up to 3,000 psi. So, a gun that has a 3,000 psi fill limit is going to be received better than one that needs to be filled to the 4,350 psi that some German guns require. The United States is not a very big airgun market in general; but for guns that develop great power, it’s probably the biggest market there is. Anyone who builds an airgun of great power would be foolish to also build it to accept a 300 bar/4,350 psi fill. Doing so would cut out their biggest potential market.

On the other hand, the United States is a relatively small market for high-end 10-meter target guns — guns costing between $1,700 and $3,200. So making a gun in that category that also accepts a 300-bar fill isn’t foolish at all. If the European market for these guns is that much larger than the U.S. market and if it’s that much easier to get the higher pressure air in Europe, it makes perfect sense to build guns like that (for reasons I will discuss in a moment).

However, making a low-cost, youth-oriented target rifle that needs a 300-bar fill would be suicide! That’s because the world market for rifles in that category is located in the U.S. We have almost a million kids each year competing in 10-meter target matches, and that’s a number that’s been verified by the NRA. That’s why Daisy, Crosman and AirForce Airguns all have models in that category, and they know that to boost the fill pressure of their guns to 300 bar would be the kiss of death.

What about the boutique makers like Quackenbush and Barnes? They know their markets well and tend to build guns that fill to 3,000 psi or less. It’s true, many of the Quackenbush Outlaw Long Actions will accept higher fill pressures and still work well, but that’s an anomaly. They’re designed to use a fill pressure of 3,000 psi.

And what about the Korean precharged guns? Many of them will also accept a higher fill pressure and still function. In their case, like the Quackenbush guns, I think the design goal was 3,000 psi, but a too-heathy valve return spring boosted the top threshold beyond the goal. With guns like these, a shooter is rewarded for chronographing his shots and establishing what the actual fill pressure of his specific gun is before heading out to the field to hunt. He can get by with a 3,000 psi fill, but time spent on the chronograph will reward him with extra velocity for the shots he gets on each fill. What it usually won’t do is add more shots to the total per fill.

Can fill pressure be a primary goal?
While it normally isn’t a primary design goal, it is possible to make the fill pressure limit one of the primary goals for the airgun’s design. Tim McMurray and Larry Durham were the first ones to succeed in doing this in a very big way when they designed the USFT rifle. With a fill pressure limit of around 1,600 psi (these rifles all vary just a little on the exact pressure limit), they get 55 good shots of .177 Beeman Kodiaks traveling over 900 f.p.s. How is that possible? Well, there are 3 things that make it possible. One is a 25-inch barrel that gives a longer time for the pellet to accelerate, and another is a huge air reservoir that stores a lot of air at the recommended fill pressure. The third essential thing is a valve and hammer that are balanced perfectly to open the valve and hold it open long enough for the pressurized air to flow into the barrel and get behind the pellet.

Even before the USFT came about, Gary Barnes made one airgun that got a notable velocity on extremely low air pressure. With his outside lock airgun, Gary was able to get .25-caliber pellets over 25 foot-pounds of energy (a 20-grain pellet going 753 f.p.s.) on just 600 psi. That sounds incredible until you recognize that airguns were doing that and much more in the 1600s and 1700s. They had to because that was about as much air pressure as they could get into the gun!

Barnes’ outside lock gun did not shoot at a steady velocity. The first shot was the most powerful, and each shot thereafter dropped in velocity somewhat. But it was still possible to get 9 shots from his gun — all from an initial charge of 600 psi. His rifle has a 32.75-inch barrel, which is needed to extract every last bit of energy from the low air pressure. And the secret of his valve is that it’s held open not by impact but by a pair of cams that come into contact and are locked to travel together through an arc as the hammer falls. The length of the arc determines how long the valve remains open. So, the velocity of this gun can be regulated by the hammer spring, the valve return spring, and by the size and shape of both cam elements. It’s an ingenious design that dates back to the very early 1700s.

Knowing that low-pressure operation was possible for a PCP, I went to Crosman in 2006 with a proposal to design a low-cost, easy-to-fill PCP single-shot rifle. I’d been told by another airgun designer that my idea was impossible the year before, but I knew from the USFT and the Barnes gun that it was very possible. The result of that project was the Benjamin Discovery.

Why fill to higher pressure?
The next question we must ask is, if it is possible to get many good shots on lower fill pressure, and the Benjamin Discovery proves that it is, then why would anyone ever build a gun that takes a fill pressure that’s extremely high? Why, for instance, would a gun need to be filled to 4,350 psi? One good answer is the gun has a pressure regulator that drops the reservoir pressure to a lower pressure that the firing valve can handle. If you can drop 4,350 psi to 1,800 psi for a valve, you’ll get many more shots from the gun than if the valve had to operate throughout a range of pressures. That’s because no matter how a mechanical valve is designed, there will always be an upper limit at which it will work and a lower limit, below which it will stop working.

While such a system SOUNDS like the perfect design, you need to consider that the pressure regulator takes up space inside the reservoir that cannot be filled with air; and the valve also needs a small chamber of air at the lower pressure where it’s been designed to operate. That chamber also takes up some space where pressurized air cannot be stored. So, there’s a tradeoff when installing a regulator. You need enough room inside the reservoir to make the regulator system worth the loss of reservoir volume.

A more sophisticated system
A better way to use air at a higher pressure is to employ a computer-operated solenoid to open and close the firing valve. Then, you don’t need either the regulator or the air chamber. The electronic valve does all the work. If you also put a pressure sensor inside the reservoir that can tell the computer how much pressure it has to work with, the computer can calculate exactly how long the electronic valve has to remain open, giving you shot after shot at the same velocity, even when the air pressure drops by 2,000 psi. This is how the Benjamin Rogue works.

While the .357-caliber Rogue hasn’t been a huge success in the marketplace, the proprietary way its valve operates gives Crosman an edge in the PCP market. If they were to put their valve on a smallbore rifle built for general hunters and shooters, and if they could keep the price under control, they might just have the next generation of sporting PCPs. I don’t mean the gun has to be cheap, either. With Air Arms sporters selling for $1,000, and both FX and Daystates pushing $2,000, there’s plenty of room for a premium-priced Benjamin sporter with the Rogue-type electronic valve. It can’t look like it was sired by a boom box and a black rifle, and it has to be quiet, have a deadly accurate barrel and a trigger to die for; but such barrels are available, and Crosman knows how to make good triggers and quiet guns.

So, GunFun1, this is my answer. Fill pressure isn’t normally the first thing on the minds of airgun designers. Many of them just build guns that work, and the fill pressure falls in place toward the end of the project. Those who are more savvy know what the market will allow, and those who are really sharp know what the market is looking for.

66 thoughts on “How do airgun manufacturers come up with the maximum fill pressure for their precharged airguns?”

  1. I’m hoping Crosman takes their proprietary valve technology and integrates it into smaller calibers (up to .25 cal).

    The problem with conventional regulators is not if but when they fail.

    The problem with a computer-operated solenoid to open and close the firing valve like the cdt, mvt and current mct is electronics. Boards fail, contacts get dirty, batteries run down, etc. The other issue I had with my electronic guns was the trigger. It felt like clicking a mouse connected to a computer. No feedback. I also had problems with electronics. Covered by warranty but the experience left me with a renewed appreciation for an entirely mechanical gun. My experience is that these more sophisticated sytems are not a better way to regulate airguns. Yet.

    Yes, I know that electronics rule our world. In our appliances, cars, laptops, etc. Until electronics are perfected in guns like the mvt and mct I’m out. Not based on what I’ve read but what I’ve personally experienced.

    From what little I know I think Crosman’s electronic valve technology could take pcp airguns to the next level and with the mct and wolverine costing around $2500 and the current rage of the mechanically regulated cricket pushing $2000 there’s room in the market for a Crosman introduction in the small calibers.


  2. BB
    I just wanted to keep reading. Every sentence was great information.

    The 600 psi gun with the cams catches my attention along with the electronic valve of the Rouge.

    Here is why. Since I as kid when I got my license to drive I was always into drag racing at the local drag strip. I learned very quick that a engine is nothing more than a air pump. The faster the air can flow in and back out the quicker you will go.

    The piston, rods and crank is what keeps the engine together. The oil pump is the heart of the engine. and the camshaft Is the brain. The valvetrain allows the engine to breathe.
    The lighter the components the better it will respond.

    Here is something I talked about for years. Get rid of the camshaft now that we have PC’s to control things like the lift and duration the valve stays open.
    Instead place a solenoid over each valve and let the computer control how long the valve stays open and for how long of duration and how much it opens. They do that with the multi port fuel injection already. And dropping cylinders off from fuel and firing. Those pistons are just along for the ride at that point.
    If it was (physically able to be done) it would be like having access to multiple camshaft profiles by just a flip a switch or a touch of a screen. Also rpm of the engine would greatly improve because you loose all your drag from your valvetrain. And guess what mileage would improve too.

    As far as air guns go having a way to adjust the valve with electronics and a program gives you a huge advantage when you are trying to control the air through the valve to the barrel. Kind of like a engine.

    Some people use Progressive controllers on nitrous cars also. The computer pulses the solenoids and allows you to run a big horsepower shot of nitrous. You can adjust what % of the horse power you want to start injecting into the engine and how long it takes to reach 100% of the mixture.
    Allows for horsepower to be placed to the ground less abruptly.

    What I’m getting at is I think if the system from the Rouge was used on more guns we would be able to go to the next level of air gunning.
    Go from a indoor shooter to a 10 meter gun to field target to all out hunting gun just by a push of a button on a touch screen. And as far as battery’s go Li Po battery’s and other types of rechargeable battery’s should perform well enough for the air gun purpose and last for I’m sure a reasonable amount of time.

    And last but not least the air pressure fill level could be changed more efficiently.
    I know it sounds like the Rouge I’m describing but just think of that system on a AirForce gun with the ease of the barrel changeability on those guns. That would be a neat combination to have in a gun.
    And the manufacturer could sell one frame with the electronics and you could build your gun with different barrels and air-tanks and be totally adjustable.

    I wonder if that would sell guns ?

    • You are on the right trail there.

      If I am not mistaken, from what I have been reading, there are two things that held the Rogue back.

      One is as BB mentioned, they missed the boat on the styling. It is a big plastic looking thingy with a good size price tag.

      The other is that the accuracy is not that impressive to those who are in the big bore market, which brings up a third point.

      BB mentioned the limited size of the air gun market. The big bore air gun market is even more limited, but it is slowly growing.

      Once AirForce brings out their new rifle, perhaps they and Crosman could do a joint venture and produce such an air rifle as you desire.

      Personally, I want one based on Gary’s and Dennis’ open lock rifles.

        • According to John McCaslin (Mr. AirForce), they are coming out with a big bore soon. It is not built on the present frame as that has been taken about as far as it can go. The new one will be offered in up to .50 bore. I was hoping they would pull it out at the last Shot Show, but I guess it wasn’t ready yet.

    • Formula1 engines use hydraulics to open and close the valves because the engines run a (limited) 18,000rpm but it’s an expensive and like Kevin mentionned it’s not totally reliable yet so it can’t be used on street engines.


      • I believe they’re actually pneumatic! Wonder how they choose and regulate those pressures!

        Remember a year or two ago when the Lotus’ CF air tank blew after their funny forward exhaust caught fire?


        • And, it looks like you both are right. Valve actuation is electro-hydrolic and the air replaces the springs.
          I think we should be expecting just about anything when the new turbo V-6 lands next year. Mercedes has already introduced their’s. And, now that we know that Honda is coming back, it looks like BMW may become an engine supplier also. Add Renault and I just can’t wait to see what they can come up with.

    • Gf1,

      The only problem I see with using solenoids on the valve train in a car is the weight and reliability of the solenoid itself. In electric generation, we use solenoids for a lot of things and they need to be reliable, but they fail regularly due to the nasty, dirty operating environment. They even fail in semi clean environments. I don’t think an engine is much cleaner… Plus the terrific amount of force needed to open even the smallest intake or exhaust valves would mean using direct solenoids that are large and heavy enough to make installation room a problem. I think cam grinds and electronic cam timing are here to stay for a while…


  3. I believe that as a design for a non-adjustable PCP evolves in the development before manufacturing, engineers tweak the individual valve dimensions (controlling flow area), transfer port flow area, striker dimensions (controlling striker mass) and finally the wire size and shape of the springs (controlling spring rate), all to produce the desired gentle rise and fall of pellet velocities within a shot curve at the desired starting fill pressure. This would be a reasonable approach for balancing any dynamic mechanism. Aftermarket experimenters have already discovered that simple spring changes can have a huge effect. The total number of turns in a spring and its pre-compression (or pre-tension) would also affect energy transfer in the mechanism.

  4. Great blog today BB, thank you. Anything pcp interests me as I’ve decided it’s the only way to go with airguns, with C02 being a close second. (Springers are too inconsistent and mult-pumps are just plain stupid for ANY application)
    I don’t agree with HPA being readily available though….maybe in Texas, but where I live my ONLY choice is a hand pump. And I don’t find pumping to 2k to be that big a deal, however…..
    After roughly 250 rounds the Benjamin pump I’ve been using failed. It can’t be rebuilt, so I either replace it or step up to a Hill pump, neither of which is cheap.
    And that’s the real trouble with pcps IMHO; People like myself, who’ve turned to airgunning as a way of being able to shoot without the high cost associated with firearms, aren’t going to drop huge wads of cash on a gun and it’s required peripherals. Add in a 3k+ fill pressure and you’ve lost even more of the market, as you mentioned above. Compound that with the fact that most airguns can’t be rebuilt and your typical firearm nut becomes even less interested-for less than the price of a Marauder & pump I could buy a beautiful N frame S&W that will last forever if maintained properly and be handed down for future generations to enjoy.

    The Marauder doesn’t even come with sights!!!

    Personally I say let the Euro’s have their high-dollar, high fill pressure pcp’s and design something for the average underpaid, overtaxed, debt-burdened American. Let us buy the oversized bicycle pumps for LESS than $100, keep the pressures low, and show a little pride in your work-Even the most “cash challenged” among us are willing to pay more for QUALITY.

    • “…Springers are
      too inconsistent and multi-
      pumps are just plain stupid for
      ANY application…”

      I have to disagree here. Many unreg pcp (out of the box) will shot with more fps variation than springer and MSP if you’re not familiar with the pcp characteristic. I have personally witness a hw77 that shoots 30 pellets with no more than 15fps extreme spread, out of the box. With careful tune, 10fps or less ES is possible. My own Sharp Innova will have approximately similar ES shooting all day long.

      And in your situation where filling to 3000 psi is difficult (actually same with my situation as well), springer and MSP are excellent choice, together with low fill pressure fill pcp like Disco.

      As to why marauder doesn’t have open sight, I think it is understandable. With pcp, 50-100m shooting is not uncommon, and without scope you cannot shoot pcp to their full capability.

      • Lee I’m sure you’re absolutely right about extreme spreads but what I meant was that springers require a consistent identical hold for every shot. Frankly I can’t be bothered to account for variations in POI due to longer whiskers on my cheek because I didn’t shave, a scab on my thumb that changes my grip ever-so-slightly, or bone shrinkage that makes me just a hair shorter every day.
        I realize it’s no fault of the gun-BB regularly posts amazing groups with just about any springer he picks up-but I’m simply incapable of that. And if I need to take out a tree rat scampering across the lawn there’s just no time to try to accurately duplicate the stance I may have been in previously that allowed the shot to go where I wanted it to.
        As for sights on the Marauder, well, we’ll just have to agree to disagree. : ) The typical suburban backyard hardly measures 75 yards diagonally here, and I really don’t see the need for a scope on a gun at that distance or less.

        • Ah so that’s what you mean with springer inconsistencies. But I still think MSP is perfect for your situation. More or less same effort with using your benjamin pump on pcp.

          As for handpump, I’d follow dave suggestion. I’m sure you can ask pointer how to do it here.

  5. I like the discovery because of the easy to fill 2000psi tank. I found the gun to be rather underpowered but that is easy to fix with a few aftermarket pieces. Gut the gun, toss in a max flow air valve, a power adjuster on the hammer spring, an extended probe bolt and a baffled TKO muzzlebrake and it’s everything the Marauder is without all the massive bulk. I have a condor too. Of the two I like the 2000psi fill better than the massive 3000psi tank, but you just can’t beat the condor for power or accuracy. That isn’t because it has 3000psi of fill. It’s because of how the gun is designed. I looked at both guns. The discovery’s air needs to make 2 90 degree bends to get out the muzzle. The air force guns don’t have any such restrictions. I suspect that has something to do with just how powerful those guns are.

  6. You say that the US isn’t a big market but Europe is, probably because of it’s more complicated firearm laws.
    But I never could understand why it hasn’t caught up here. Why aren’t more airguns available here?

    There’s a weird attitude towards guns here, air or fire powered. Firearms are considered evil by a lot of good thinking people and airguns are viewed as toys or non-real guns by others so they kinda fall in no mans land.

    I don’t get why more people aren’t using airguns, why gallery guns disapeared? What’s not to like about airguns? Low noise level, fun to use, accurate, relatively cheap…

    I saw the ad for the new Hammerli AP20, will you be testing it? From the minimalist look of it I tought it would be cheaper.


      • I wouldn’t call it “nice” but it certainly looks functionnal. I like how you can put the air reservoir horizontal or vertical but it’s close to the Walther LP300 price wise and quite more than the Alfa proj. Do you think it has what it takes to compete?


        • J-F,

          I have seen shooters compete at the regional level with a Daisy 777, so in the hands of a real shooter, there is no doubt that this pistol can compete.

          But if a shooter is ranked at the world class, why would they shoot anything but the very best? Those superior ergonomics make it so possible to carve out a couple extra points that it is absurd to think of using anything less.

          At under a thousand dollars, this pistol is for private shooters who don’t compete. It is affordable, and yet accurate.

          When it comes to competition, you run the best. Nothing less will suffice. But I’m only talking about world-class competition, so just a few hundred shooters. You can get there with lesser guns, and the AP20 fills that niche nicely.


    • I’m sure the answer to why airguns are not more popular is that since firearms are allowed in the United States, people wonder why you would get an airgun instead of a firearm. It’s probably related to the whole drive for power thing. I don’t believe most people think of shooting in terms of long sessions of low-powered shooting even though it is a lot cheaper and at least as fun.


  7. That’s what I think also that solenoids being used for engines is maybe aways off yet.

    But the solenoids could still be placed inside the valve cover and have that area dry from oil. The valves could be oiled through ports in the head like how the cam and crank and rods are oiled.

    When we build engines we put oil restricters in the block to limit oil to the top end and keep more oil pressure in the bottom end. The valves don’t need as much oil as the crank and rods.

    And BB I know. That happens to me for some reason when I start thinking about things I want to say.
    I write to much!

    But matter of fact that makes me think of something else. Here’s the million dollar question.
    As well as you write and as much as you know about air guns and other guns for that fact.

    (here goes the question)

    How come you haven’t wrote some kind of book about that yet?
    I would make a bet that it would sell.

      • BB, rather than writing new book, why not compilation of this blog, categorized by subject. Maybe not individual review but rather what’s work/not fundamentally. don’t forget the friday blog as well.

        I’ll definitely buy such book.

      • I’m sure all the blog writing must be why your book hasn’t appeared sooner. Only so much energy to go around. On the other hand, with all of this writing and thinking about the subject, you could turn out the book much faster than anyone else.

        I just found out that my library book is going to be printed in March 2014. I’ve heard from the final editor and Mikey likes it! I must say that with furious commenting on the blog, I didn’t have any problem with writer’s block.

        But there are books and then there are books. I tried to make my library book more interesting than the norm which is not saying that much. Basically that you won’t fall asleep within the first few sentences. But my recent evenings have been engrossed by this very interesting novel. It has to do with a very weird F.B.I. special agent named Aloysius Pendergast. There is a long convoluted plot in which his wife is kidnapped by latter-day Nazis who want to perform nefarious experiments on her. He finally runs them down in a desert in Mexico, attacking their SUVs on a Ducati racing bike. As one of them flees, Agent Pendergast assumes a kneeling position with his M4 and drops the guy at over 500 yards in the faint light of early dawn. But the real villain of the piece is a white-haired elderly German bodybuilder who goes sprinting out of range… Now that is the sort of book to write.


  8. Off Topic

    Garvin, the creator of the Falke forum on Network54 has in collaboration with some other airgunners, created an airgun collecting magazine in the form of a PDF. The magazine is available for free, the only stipulation is that you pass it along to anyone else you think might be interested. I have downloaded it, and it is quite well done.

    Just open the link below, then click on the blue ‘Download file’ button.


    There is a superb article on the Diana 27 that was written by Mike Driskill, who has posted on this blog from time to time.

    • That’s fantastic! Quite well done, I guess so. You guys can chat about electronic triggers and HPA all you want. Is it just me, or is there anyone else who would rather have a beautiful vintage pistol to look at every day or an old, old long rifle. Now that I think of it, it is the same for me with motorcycles. I like my guns and my motorcycles just like my woman … old.

      • You are not alone out there. As I posted closer to the top, I want the low fill pressure open timed cam lock that BB referenced. I have personally drooled over Gary’s creation and pissed off Dennis asking him about his.

        We came to the knowledge of these type too late it seems. The boutique air gun manufacturers experimented with these air guns back in the late 90s. Dennis even made a run of them and found to his dismay that at the time, the market for this type of air rifle was extremely limited and it took him several years to sell them all.

        The big manufacturers are not going to pick them up because they need to be made to a higher level of quality than other types and they have not as of yet seen a market for them.

      • I like my airguns the same way I would like cars (if I had the money) and women (if I lived in the middle east and could have many of them) plentiful and beautiful 😉

        I have very ecletic taste, I like a vintage Camaro as much as I would like a new CTS-V. Given the winning numbers the first cars I’d buy/build would be a gasser Nova and a CTS-V, both end of the spectrum and then all kind of stuff in between.

        You can have a nice wood and shiny blued steel airgun and an airforce rifle with more of a black rifle look.
        I like my old Slavia 618 as much as I like my new Steel Force.

        It’s what is great with guns compared to cars and girls, they’re a lot less expensive, take less place and won’t get jealous of one another and are a lot less expensive LOL 😉


  9. BB

    It doesn’t matter how long it takes to write the book. It matters that it gets done.

    And as far as what I like about old cars and guns is; I like old ones and everything in between to the new stuff.

    And as far as women go I got to watch what I say; My wife and daughters read the blog at times.
    So yep I love my wife and daughters. 😉

    And RR what you just said about the guns from Dennis and Gary. Ain’t it funny how when something is made and released to the public for sale if the timing of the release is not at a appropriate time the sale of that product could fail.
    And yep its hard for the big name company’s to produce one off specialty models. Engineering, tooling, equipment and set up all cost alot of money. Then you have to throw in the fact of design change if something don’t work as planned.
    So I think the guy’s like Dennis and Gary (and others of course) are doing a wonderful job of making history right in front of our eyes as we speak. History has to start somewhere.

  10. Bit off topic…

    The YJs have been starting to bother me this last week. The cool night weather must be telling them that it’s becoming fall. Good time to try baiting them.
    Had thoughts about cleaning out a weed sprayer and mixing up a gallon of sweet cider, some peach and pear juice, and spraying it in a tree to get their attention. Of course setting out bait to go with it. Anybody ever try this ? Squirrel skins and guts work, but I don’t have any at this time (draws big flies too).


    • TT
      The Yellow Jay’s is what I guess you mean. We got Blue Jay’s. The Blues are mean birds. They will go after you and they will steal the young out of song bird nests. And I have seen them get baby squirrels.

      Is that what you mean buy the YJ. Or Yellow Jackets. Got those and they are mean too.

      I read again and what you said about sweet cider it must be Yellow Jackets.

  11. Water is an incompressible fluid, but air is not. Is there something to be gained by compressing the air more? Probably not. I think it was mentioned on the blog long ago that it takes a fair amount of technology to compress the air as much as is done now, and besides there is the point about a regulatory mechanism for releasing the air at the right pressure.

    My own thoughts on maximum fill pressure have, naturally, to do with danger. Based on a snippet of engineering that I heard, I would guess that they would designate the maximum fill pressure well below would it would take for the reservoir to burst. What would be the consequences if it did? Would it be as dangerous as blowing up a firearm with overpressure? Or would the reservoir just pop with no harm done?

    Gunfun1, nothing wrong with mentioning bad Chinese manufacturing processes–a theme that we have covered many times. I think it raises an interesting point. We hear about dog-eat-dog capitalism, the rat-race, and other expressions of intense competitiveness with the free market. But the Chinese have raised it to another level. They have flooded markets with shoddy goods. When I visited there, the waiters would ignore you and act like they were doing you a favor to bring your food. My tour guide was trying to show the group the goods of a local vendor, and the vendor told her (as I heard in translation), “If you’re not going to buy something, get your ding-dong cock-a-doodle do self out of here.” It wasn’t complimentary. So the question is, notwithstanding the likes of Donald Trump and Bernie Madoff, could it be that for capitalism to work for a whole society and reach its full potential that you need a threshold level of honesty and consideration for the other? Something that the Chinese do not appear to have accepted yet.


    • About the Chinese thing, my cousin who spent a few years there was telling me that to the Chinese, caucasian beings are soul less. They would cut in front of him in line and would act as if he just didn’t exist, they would often argue with each other (as is apparently common there) with him in the middle without giving him the least bit of respect.
      So I think it’s only normal that they don’t pay much attention to the goods they manufacture… they’re making cheap work for people who they don’t consider so why would they put any kind of effort in it?

      He also told me that the second you went close to the outside limits of major cities people would be gross, loudly burping, farting, spitting and every other gross thing that you can think of that involves bodily fluids, gases and functions.

      He said his favorite country had been Japan even if they we’re somewhat racist, having places where non-Japanese were just not allowed, it was still an awesome place to visit.

      He spent a few years in China and other Asian countries and a few in Vegas, Germany, France and now lives in Hawaii. I think he has more stamps in his passport than I have airguns 😉



      • J-F,

        Unfortunately, the racism is a real issue here as well, as it is brought over here from both China and Japan. I’ve personally worked on projects, including a missile defense system, where even whites were excluded. Very disturbing, and very wrong.

        In the one company where the missile defense system was being developed, a Chinese employee was discovered to be hoarding defense related documents. What I couldn’t understand is that rather than bust the guy for military espionage, they busted him instead for “industrial espionage”.

        The situation was so bad at this company that I reported the activities to the FBI, and they showed zero interest. The plant eventually closed, but I believe that a lot of damage was already done.

        We are giving all away at all levels, including our national security. I don’t think that people realize this.


    • Matt61,

      I’ll add that doctors warn about buying vitamins, mineral supplements, and pretty much anything health related from China. My wife and I will call manufacturer’s directly to find out where the product is actually grown or made. Mineral supplements are supposedly one area where the Chinese will include what doctors consider to be very dangerous to one’s health.

      In addition to this, China is infamous for intellectual fraud at all levels, including “research” and credentials (e.g., diplomas). Trouble is, I’ve worked for MANY people from China and Taiwan who themselves don’t trust anything Chinese, often saying that China is effectively lawless.

      Another thing that bothers me is the fact that when American corporations decide to have their products made in China, they are often giving away precious secrets. There is very little good that comes from this, other than someone’s bottom line. These days it seems that profit is the ONLY value. That wasn’t the case before 30 years ago.


    • My own thoughts on maximum fill pressure have, naturally, to do with danger. Based on a snippet of engineering that I heard, I would guess that they would designate the maximum fill pressure well below would it would take for the reservoir to burst. What would be the consequences if it did? Would it be as dangerous as blowing up a firearm with overpressure? Or would the reservoir just pop with no harm done?

      Well, first thing to consider… Take an AirForce tank (which is, granted, on the large size for airgun reservoirs)… Full load is what, 200bar? Now imagine putting that tank inside a refrigerator — how much space does it take?

      Will that refrigerator hold 200 of these tanks, with the door closing? That’s about the space that the air in the tank is going to occupy if, somehow, the shell of the tank were to vanish.

      Now consider the average firearm cartridge. Let’s be generous, since I picked one of the larger airgun reservoirs… Let’s pick a rifle cartridge about the size of a .45-70 AND lets be generous and assume a rather high pressure: 40000PSI (I suspect the actual .45-70 is probably more like a 25000PSI round). If 200bar is ~3000PSI, we are looking at about 13x the pressure in a volume the size of a fat finger…

      I have a feeling that 2600 rounds of .45-70 would easily fit the refrigerator — having one go off inside probably won’t even “burp” the door. The air reservoir, OTOH, will likely blow the door open.

      Or, for a visual… Mythbusters has cooked off rounds inside an oven; and the oven survived. In contrast, they’ve knocked the valve off compressed air tanks and the tanks have penetrated concrete (brick) walls.

      • Wulfraed

        I saw that on Myth Busters. Very interesting.

        And I got those no permission to post screens also. With very simple comments.
        Like…(I think something can be learned by that).
        And that was all I said. Nothing else.

        Seems to me the system may not allow multiple posts in a given time frame.

  12. You guys hit the bulls eye on this.
    Exactly what I’m talking about. The low quality, attitude and the fact that they will buy company’s if they get a chance just to have ownership.
    We have run out of material at work because China has been buying up as much scrap metal as possible. Just recently and in the past.
    Kind of a bummer when the guy out there is working hard to run his machine and make quality parts 6 days a week or more (and of course all the other people involved to keep things going) gets sent home on Monday because they cant get material. What do you tell the bill collectors and your family.

    Oh I know China made me do it.

    And like I originally said I shouldn’t of posted about this.
    But in the old days the company’s would try to hand it down to keep it in the family. I think now the other company’s have become to powerful and there are many,many greedy people out there. So selling just happens now days.

    All I can say is if I did start a company and worked hard to make it into something and it got taken over for some stupid reason I would not be a person to be around for no telling how long,

  13. Oh And Matt 61
    You wouldn’t believe the force of the air if you de-gas a Marauder at 3000 psi to quickly.

    This is something that happened in 10th grade in my machine shop class. This is true I’m not making this up.
    Somebody was brazing with a oxygen/acetylene torch and they didn’t know they was heating the oxygen bottle right below the gage (not that it mattered were it got heated).
    Guess what the knob and gage assembly got blew into the drop ceiling and the tank fell over and got knocked out of the chains that held it in the roll around dolly. The tank flew across the shop about 10 ft. then got stuck in the concrete wall. Everything that was flying around just missed everybody. Nobody got hurt. But alot of questions got asked.

    So yeah no telling what can happen no matter how simple it looks.

    I got a few story’s I can tell about with things that went wrong. But the biggest thing is; I wish I didn’t have to have them story’s to tell. But I learned from them and I’m glad nobody got hurt.

    • GF1

      Just thought of something…
      Is it possible to de-gas the Benjamins too fast ? It is really about the same thing as a low speed tank dump . If you dump the tank on an AF rifle, you can’t do it very many times before you scrooch the valve. Seems like it only takes two or three dumps to do in the valves. These are high speed dumps.


      • TT
        I imagine it could mess the valve up on the Marauders if you did it to fast and to often. I only shoot compressed air so I don’t switch back and forth to air and CO2.

        But if for some reason I need to lower the fill pressure on my Marauder I will dry fire it down to the fill pressure I want (and yes it is ok to dry fire a PCP gun just in-case somebody doesn’t know).

        I will use the de-gas tool also at time’s though. Just depends on how much air I need to let out. The de-gas tool works good if it is alot of air that needs let out. It will do it pretty quick verses dry firing which will take a little bit of time.

        And the de-gas tool is about the only way you can get a Marauder to fire again if the valve goes into full valve lock. And the tool will allow you to let the air out gently.

  14. BB and others

    I just found an HW55. Seems like it is in great shape. Not sure about seals or spring, I presume those would need to be changed based in experience. Not sure about model either. It is not the Tyrolean and it’s not the target model that BB reviewed in this blog. It has the locking lever and might have been reduced in the 70s.
    It has the original aperture rear sight and front globe. I am in love with this thing but I would only buy if it is at least a little bit of a bargain. Is $300 too much? I feel like it is.
    Any input wold be appreciated, and yes, I am lacing an order for the blue book!


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.