The best of B.B.: Can nitrogen be used in PCPs?

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • The argument
  • Liability
  • So, is nitrogen dangerous?
  • Oxygen can kill you!
  • So what? We’re talking about nitrogen
  • What about other gasses?
  • Show some respect

Tomorrow is Thursday, December 24. It’s Christmas Eve. On that day I’m running a special blog that allows you readers to do most of the writing. We will all tell which airgun we would like to receive for Christmas, and I will start it in the text. Be thinking about the one airgun you want the most this year.

I realize that not all readers celebrate the Christmas holiday. But don’t let that deter you from commenting. Whether you celebrate Christmas or not, this exercise is open to all readers.

I’m running some Best of B.B. reports to give myself some time at Christmas. I have family and guests this week, and I can’t get to the computer as often as I would like. This report was first published back on January 15, 2008. I have updated and added a few things to it for today.

This report was requested by reader Pestbgone, but from my years working at AirForce I know that a lot of other shooters also wonder about it.

The argument

Here is the argument – Air is composed of approximately 78 percent nitrogen, 21 percent oxygen and the remainder a smattering of other gasses. With nitrogen as the principal component, these people want to know why a precharged airgun can’t be operated on it exclusively. Nitrogen is more readily available to many of them (welding), and if it can be used it will lessen their airgun support problems immensely. I will address the issue today.

What I used to tell people who called in to AirForce with this question is that we only recommended our guns for use with breathing air and no other gasses. The seals in our guns were selected for use with air (a true statement) and we could not be responsible for their use with any other gas (also true). What drove that answer was product liability.

Liability

Do you have any idea of how much money an airgun manufacturer pays EVERY YEAR for liability insurance? It’s a heck of a lot more than most of us make. I’m not talking about the level of liability the company is insured for, just the actual cost for the coverage — the bill! The cost is based in part on how many guns you expect to sell, so as you prosper, your rates increase, because the insurance company’s exposure increases.

To even get covered a company has to have solid product literature, solid technical data on its products and a solid base of information that directs the customer in the safe use of the product. Remember, and this is no laughing matter, that there once was a man in the U.S. who sued a lawnmower manufacturer for damages he received when he picked up the mower deck while his lawnmower was running, in an attempt to trim his hedges! He won a settlement for that! That’s why all mowers sold in the United States today have a kill switch that must be depressed at all times for the mower to run. It’s that spring-loaded bar you have to squeeze when operating the mower.

So, is nitrogen dangerous?

Will nitrogen hurt your PCP? No, it won’t. Nitrogen is an inert gas that doesn’t react with most things. Oxygen, on the other hand, supports combustion, and the oxygen that both medical personnel and welders have access to has been known to blow up airguns!

Oxygen can kill you!

Now, here is the bad news. While nitrogen is relatively harmless, oxygen can kill you! Oxygen supports combustion so violently that it overwhelms people standing near. A fire in a room saturated with pure oxygen is so violent that people inside have almost no chance of escaping.

Do you think that nobody would be stupid enough to try using pure oxygen in a PCP? Think again. It has happened many times, once probably resulting in death. That one happened in England in the 1990s, but take a look at Pyramyd Air’s experience with it.

Fire 201 left
This Fire 201 9mm rifle was filled with oxygen instead of air. The caliber doesn’t make any difference. It’s the oxygen that does the damage. It caught fire while being shot and melted the rifle as seen here.

This is what happens when a VERY HOT flame is held against aluminum for a long time! It looks like a cutting torch has been used on this gun from the inside out. This was a Fire 201 9mm rifle.

Fire 201 right
Note the discoloration of the anodizing. Forensic scientists use clues like this and the bending of the steel barrel to determine how much heat caused the damage and how long the fire lasted.

This is the SECOND time Pyramyd Air has had to deal with this same problem. The first time a medical technician called in to ask them why his Career 707 was shooting a blue flame out the muzzle on every shot! Had his rifle exploded and he survived, don’t you think he would have tried to make them pay for it?

So what? We’re talking about nitrogen

What this has to do with nitrogen is simply this, PEOPLE DON’T PAY ATTENTION! For instance, nitrogen can come in tanks compressed to 6,000 psi instead of 3,000 psi. I once met a guy who thought the way to fill a PCP was to connect the hose to the gun and open the valve as fast as he could. The gun filled right up in a couple of seconds, though it did get hot. If you don’t understand why, please re-take your high school general science class where they explained about the heat generated by compression.

Now, you take a paintball player who has access to nitrogen in 6,000 psi tanks and the same attitude as the guy I just described and you will have large pieces left to bury. But, take a medical technician with the same attitude and access to pure oxygen and the pieces will be both smaller and probably well-roasted.

What about other gasses?

What about helium, people ask? Yeah — what about it? Will is make a pellet go faster? Yes. Do I care? No. I have firearms for whenever I need to go faster or hit harder.

Show some respect

Guys, these are AIR guns, and they need to be operated with some respect. Yes, the shark blowing up in the movie Jaws was Hollywood theatrics, but we are dealing with some serious technology here, and we need to respect it. It’s funny watching someone else on You Tube shoot a propane tank with a .22 rimfire and get consumed in the resulting explosion. It’s not as funny when you’re the one at ground zero.

So, what am I saying? I’m saying that our current precharged airguns are built to operate on breathing air and that’s how they should be used. Let’s leave the serious accidents to the skateboarders, stunt cyclists and the people on America’s Funniest Home Videos.

Editor’s note: Since this report was published, AirForce Airguns has started advertising that their guns may be used with compressed nitrogen, as well as air.

99 thoughts on “The best of B.B.: Can nitrogen be used in PCPs?


  1. I am often amazed at how stupid some people can be, but I am even more amazed at how a group of people can reward a stupid person for being so stupid.

    Now as for the oxygen, I could see where that might slip by. I cannot recall ever being taught in school that it is not a good idea to mix pure oxygen and petroleum products. You would think that someone who has ready access to oxygen would be informed of such, but obviously not everyone was or they did not listen.

    Although I am familiar with diesel engines, I did not truly understand the phenomenon of dieseling until I became interested in air rifles. Despite my research and being cautious concerning the introduction of petroleum into the compression chamber, one day I experienced a massive detonation with my Gamo CFX that quite literally blew out all of the seals. It sounded like a .22 rifle going off and produced a considerable cloud of smoke.

    All I can figure is that I had just had PA replace the spring with a gas spring and either they had accidently introduced grease into the compression chamber or the piston seal failed and allowed grease in and caused the detonation. PA was nice enough to rebuild my CFX, remove the gas spring and replace my old spring and refund my money. The service manager at PA still remembers my Gamo CFX.

    This is the same effect. Pure oxygen or compressed air and petroleum products do not mix. When possible, I always use a synthetic lubricant. I know that it is safe to use oil on the leather seal of my 1906 BSA, but I still use silicone chamber oil, just to make sure.




    • RidgeRunner,

      I think it speaks a lot about this Blog that it stays relatively sane. I am sure I am not the only one that is lucky to have both eyes and most of all 10 fingers at this stage of my life. I think it is a tribute to Edith and BB that the blog has stayed mostly factual and continued on a safe and sane course.

      At a very young age I was made the family welder. I think it was because no one else liked it. I don’t know, my dad was terrible. Or maybe it was just a way to have me do it. So I had access to lots of scrap iron and liked firing projectiles and making rockets every way I could think of. A teenager can think of a lot of stupid ways to do things and I was a prime example. I am very lucky to have come through it all with minor injuries.

      Have a very merry Christmas and a safe and sane New Year!

      Don.


  2. I do remember high school chemistry when we made oxygen and hydrogen through electrolysis. We were allowed to light them off with an inverted glass beaker! I don’t believe I will get into pcp stuff since I seen what happens when one gives in to the dark side. I did go to an early show of star warz and enjoyed it so maybe there’s hope yet.



    • Mr. Rob,

      By the way, read my rather windy post above. It is possible to have serious explosions without it being a PCP. None of these things are toys and all should be handled with respect.



        • Mr. Rob,

          Yes, it is very seductive and it can be very expensive, but I have a couple of sproingers that will put a hurt on a thin wallet and I am looking at a couple more that will not do it any good either.

          Just to lure you in, a Discovery with pump is not that expensive. 😉


      • RidgeRunner,

        And as B.B. pointed out in a previous blog about CO2, a refillable CO2 cylinder filled full of pressurized liquid CO2 with no gaseous CO2 inside becomes a potential bomb, especially when heated, because there is no space for the liquid CO2 to evaporate and expand into.


  3. I was schooled on the dangers of pure oxygen when I learned about welding. What makes me wonder is the tank of inert gas that is part of a MIG welder. It is something I would not try, only ponder.


  4. Can you imagine the result if you charged with O2, then lubed your pellet…the detonation could be interesting…
    Maybe we could convince the Myth-Busters to try it 🙂 They’re experts 🙂

    BTW I am a degreed engineer, and understand the risks associated with both O2 and N2…I’d take N2…less oxidation on the seals, but if you get a bad N2 leak, it could fill a room and kill you (by pushing all the o2 out)

    My dream air rifle is an HW77 with a gas piston.



  5. Hi BB. This is my first ever comment! I’ve been an avid fan of your blog, and over the years I’ve collected a number of airguns, in approximate descending order of “greatness” (all .177): Walther LGV Challenger, Weihrauch HW50S, Gamo Compact, Diana 25 (trigger is simple sear direct to piston rod), Baikal IZH61 & IZH53 and a Chinese Westlake B2 (which looks like a scaled up Diana 25 copy). I love shooting all of them. I’ve made a spring compressor and have opened up both the Diana and the Westlake – cleaning, lubing, improving their performance noticeably. The tinkering is great fun.
    Can you please give me advice on:
    1. How to practice standing pistol 10m and standing rifle 10m target shooting – drills, tips and techniques.
    2. I want to fit a diopter sight to the HW50S to practice standing 10m target shooting. How should I ensure that the sight picture is the best for that? The front sight has a selection of pin shapes and circular apertures.
    Thanks!


    • Chuckglider,

      Welcome to the blog.

      If the glider in your name refers to the sport of gliding, know that reader RidgeRunner is also a glider pilot.

      Now as to your two questions, The HW50 is a great rifle for a peep sight. My personal choice would be to find a used Weihrauch peep sight, which other HW rifles have used in the past. In fact, one of the HW55 rifles was actually an HW 50 with that peep sight mounted. That HW 50 isn’t the same one as the one that’s currently selling, though. You have a more powerful rifle.

      Any good peep sight will work, and those made for target rifles will be the nest.

      As for learning how to shoot 10-meter pistol, I wrote a 7-part series on that years ago. Look here:

      /blog/2008/08/10-meter-pistol-shooting-part-7/

      B.B.


      • You see, that is what I mean – this blog is a treasure trove! It even has a 7 part series on exactly my question – thanks for pointing me there. I will read it with interest.

        Yes, the glider refers to sailplanes – I used to fly full size ones mostly in the UK, but I have flown solo over the Canadian Rockies. “Chuck” is “throw”, as I’ve also been known to dabble in the art of free-flight hand-launched gliders – which is immense fun, and bittersweet when you watch your model fly out of sight, going up to cloudbase.

        While trying to research standing air rifle technique, I found this gem about Pat Spurgin’s Olympics win – 393 – which I believe was a higher score than the winning man! Wow.
        https://www.youtube.com/watch?v=chEu55Tm28w

        May I also say that I was very moved reading your blog posts in August, about your good wife. God bless you all and I wish you a great Christmas.

        Harjinder (aka ChuckGlider)


  6. Go with BB on this one.
    Wise to remember two things.
    1) “Nothing” really can kill you. Pretty quickly, too. Ask any designer of space suits.
    3) Oxygen is certainly necessary but too much, wrong place, wrong time can have unpleasant “unanticipated consequences.” The whole world does not necessarily operate at “sea-level” and “room-temp.”
    I once closely witnessed a remarkably ignorant fool light a cigarette in a high-oxygen environment. The resulting exploding Marlboro was instantaneous and remarkably spectacular. Enough so to make a life-time impression on the fool. Gave me a memorable blister on the tip of my nose, too.


  7. Good morning. Snowing like crazy this morning. Another air gun shooter is going to pick me up, meet another guy who has a nice 10 meter indoor range and throw some lead. Hopefully hit some targets., I would like to see some of the more popular “read cheap” pellet pistols to be able to shoot BBS,. I am not an engineering type so can’t figure out how to put a magnet near the breech of my Browning Buck Mark, but boy I would like to try it on BBS. Current studying how the magnetize BBS, If the BB was magnetized maybe it would stay in the breech until firing. I can see me getting a BB GAGE, sorting BBs , then Magnetize them and shoot them in my Buck Mark and Beeman P17. Imagine having a BB pistol with fully adjustable sights, fairly long barrel and enough power to punch the paper . Gotta go and shovel @#$$% snow.


    • K7uqshooter,

      This has to be the first time, for me anyway, that I have heard someone wish a gun shot BB’s instead of pellets. Usually it’s the other way around. What is your reason?

      G&G


    • K7
      How about a CO2 pistol with a 499 barrel It would have two triggers: one to work the BB feed, the other with a decent pull to actually fire it. Good sights, target grips…I’ll bet it would be a fun gun and Daisy might even sell 50 of them…
      Until then maybe lead BB’s would work in your other guns ??? They come in several sizes.
      Fido3030


    • I would not think those guns would do well with a bb due to the bb being “undersized” for the bore and the guns are rifled instead of smooth bore. But now I’m all for building/making more bb guns with better smooth bore barrels and for better bbs. Just my 2 cents.


  8. B.B.,

    Nitrogen went into a bar went into a bar. Before nitrogen could even sit down, the bartender said, “Sorry, we don’t serve your type here.” Nitrogen didn’t react..

    Michael


  9. N2 (nitrogen) seems to be gaining popularity with airgunners. Most seem to rent their 6,000 psi tanks/cylinders from welding shops that will even come to your home and replace it with a full tank when needed. Some airgunners are even buying their own N2 cylinders.

    Once upon a time I understood this since the ability to have someone (fire department, dive shop, paint ball shop, etc.) close by to fill your scuba tank or carbon fiber tank isn’t convenient or isn’t even an option for every airgunner.

    Since the introduction of very affordable and reliable compressors that can quickly fill an 88 cubic foot carbon fiber tank to 4500 psi I no longer understand the attraction to N2.

    kevin


    • Kevin,

      You bring up an excellent point regarding 4500 psi compressors. I remember years ago B.B. wrote that what airgunning needed perhaps more than anything else was an electric (110/120 specifically) compressor that could fill up to 4500 psi and cost under $900 or so. Right now we are almost there. I see air compressors specifically marketed to airgunners and paintballers for just slightly over $1000, usually with free shipping.

      I still think there is “a ways” to go, however. One still must spend $400 – $800 on fittings, hoses, gauges, and a tank. The end price is still $1500 – $2000.

      Michael


    • Kevin,

      The least expensive compressor I am aware of costs app. $1100 and you still have to buy a shop compressor to add to it. Also, it takes 11+ hours to fill a 4500 psi, 88 C.F. tank. I still can’t convince myself it’s worth it. I guess I’m fortunate that a trip to the dive shop is only about a 1 1//2 hour excursion. That’s a round trip including the time spent at the shop.

      G&G


      • G&G,

        There are now multi-stage electric air compressors that are rated to produce up to 4500 (or at least 4350) psi that are one-piece units. They cost about as much as a Shoebox8 alone. Because their fill rate is a bit too fast to fill, say, a Marauder, one would really need to buy a small carbon fiber tank (say, 18 cubic feet) to fill from the compressor and then very slowly fill the marauder from the tank. At this point in time, the one advantage to a Shoebiox is that one can fill an airgun directly from it (and the shop compressor you must purchase to act as a first stage going into the Shoebox).

        No matter how you slice it, buying your own setup costs a minimum of $1400 or so. When that figure drops below $1000, then I’ll bite, but not before then.

        Michael


      • G&G
        I got one of the first model Shoebox compressor when they upgraded from chain drive to belt drive. They were just a little over $500 then. And mine didn’t have all the bells and whistles. It was just a base model. I think Shoebox still overs a base model that is around 700 or so dollars. They have the duluxe model I guess you call it that is above $1000.

        But I have to say I totally like mine. And there’s a couple ways you can go about filling a gun when you have one. First I never have got one of the big 88 cu.ft. tanks. But I did get a 90 cu. inch Benjamin buddy bottle.

        The Benjamin buddy bottle would fill my Marauder around 7 or so times. And that was a bottle pressure from 4500 psi down to about 3200 psi. It took about 45 min. for the buddy bottle to fill back upto 4500 psi. To me that’s not bad if you figure the gun was let’s say getting 20 or so good shots. So that’s 140 + shots you could get from your Marauder out in the feild with the Benjamin buddy bottle.

        And another reason I like my Shoebox and how I use it the most now at home when I shoot. I just fill my guns right from the Shoebox while I’m shooting my springers. It will only takes like 5-6 minutes to fill my .25 Marauder and the Talon SS.

        I love my Shoebox and can’t see it any other way. And with the cost of my Husky oil-less, and I stress the word (oil-less) shop compressor. The fill hose from the Shoebox to the gun I probably have $700 in the set up. Of course that’s not counting the Benjamin buddy bottle. Even counting the bottle I’m right at the $1000 mark.

        And truthfully I don’t even use the bottle. If I go out in the woods by the house the Marauder and Talon SS both get a good amount of shots to keep me buisy for a while out there walking around. So when its time to refill I just walk back to the house hook the gun up and turn the Shoebox on and set down and relax while it does the work.

        Yes I like my Shoebox. 🙂


  10. B.B.,

    Sorry, I can’t help myself. Two atoms are walking down the street. One atom says to the other, “Hey! I think I lost an electron!” The other says, “Are you positive?”

    Michael


  11. B.B.,
    The real problem with nitrogen is that I can’t get this nitrogen stuff to separate out from the air as the air goes through the hand pump and into the rifle’s tank. Do they have hand pumps that can do that now? I don’t seen any listed for sale on Pyramyd’s site. 🙂 🙂
    William Schooley
    Coach
    Venture Crew 357
    Chelsea, MI




    • Chris USA
      Reb was talking about the dry ice and pressurizing a air gun resivoir.

      And by the way I know some people like to leave their known shooters alone.

      But you know me as I heard someone else say. I’m still thinking about how that 499 project is going.

      And maybe tomorrow’s Christmas Eve blog about what air gun we would like to see under the Christmas tree this year should include air guns not made yet. Anybody ever hear of a 499 that requires the artillery hold but shoots like a 10 m pellet gun out to 20 yards. 😉


      • GF1,

        The dry ice was interesting. I was/am asking how it plays into todays discussion, if at all. What is it ? What gas does it give off as it melts or evaporates? Dangers? That kind of stuff.

        As for the 499, the piston will be the biggest challenge. The spring is do-able. I need to figure out if there is any room left at the front of the piston at full stroke. If not, I will need to move rearward to build it up, a new one. O-ring or square-cut o-ring at that point. Maybe a quick brake cylinder hone. Vortek outer guide looks ok with some mods.. Inner guide a no-go. May go homemade there. Will take my time. If the fps goes to 400 vs 200, but accuracy suffers, I will go back to stock. My gut is that will work though.

        I suppose you are too busy at work to “whip” up something? Thinking aluminum. 1 local shop. Some pics this weekend.

        Merry Christmas,….Chris


        • Chris USA
          Off till Monday and only working that day next week. And new owners take over Monday. So don’t know how things will be.

          But I do believe it will work. I bet the factory spring will give more fps if you can get the piston to seal better. I would go that route before you bump the spring up. That way if you want more fps then you know you can up the spring size.

          And like I always say. You never know till you try. If it don’t work and you put it back to factory condition who will know. Well other than everybody reading the blog. But seriously I would be doing the same if I had one.


          • GF1,

            Thanks,…I guarantee that you would be doing (other) things as well. You would be amazed. Will try local first. It will be a one time deal. Spring and piston. Beyond that, there is nothing other than a full re-design of the guts. Ain’t going that far.

            New owner’s,….. again? Been there, done that, ain’t no fun. This time though it seems to be working out. The downside is doing more, with less. Ugggh! Chris


            • Chris USA
              I’m sure I would try to change the gun around.

              I can still remember mom asking why I just took my new Christmas present apart.

              Then dad coming in and saying. Don’t worry about it. If he messes it up he won’t get another one. But if he makes it do what he wants and it works. Great.

              No just new owners now. Took this long to get things agreed on I guess I’ll say.

              And doing more with less is where we have been. This guy is suppose to have money. He actually was our competition for years. The guy is like 3rd generation family owned work in all the different aspects of the company guy.

              We’ll see how it all goes. Im just imagining what all can transpire. I did side work with other machine shops that went through this in the past. All I can say is it will get interesting for the employees.


        • Chris,
          So cool on the 499. Is the dissassembly like other Daisy lever actions, (remove stock etc., push in on spring from rear, pull locking piece up and out and then pull spring and plunger assembly out rear) or is it completely different? I have spare 499 barrel I’m thinking of putting on another airgun, not sure which.
          Fido3030


          • Fido3030,

            Never been in another one. The Red Ryder seems to have a similar set-up. That may be the next “victim”. 😉 Your description sounds like that’s what it is though.

            That spring looks like it need’s a special tool though, or should I say, that it looks like there ought to be one anyways. Got it out with a bamboo squewer though. Go figure? The chopped TX 12fpe spring may take a little extra effort though. We’ll see. Thanks for the interest. No promises. Consider me the “Guinea Pig”. 😉 Chris


            • The special tool is basically a Dowell with a horseshoe shape ground in the center to clear the trigger assembly and apply even pressure on both sides of the spring that are visible.
              I’ve got a mop handle I’m gonna try to make one out of, if I can just find my dremel.



                • Thanks for the compliment! My mental capacity is still about where it needs to be however my physical coordination is severely lacking.
                  It’s tough doing everything with one good hand!


                  • Reb
                    I’ll bet it’s a hassle. I have always been a hands on guy.

                    Heck a cut on the hand or finger causes a problem if its in the wrong place.

                    When something ain’t working right on the body it can make things very difficult.

                    But you know you do good. You always seem to get done what you want.

                    Keep on keeping on.


                    • I’m still hangin’ in there but it is frustrating.
                      I’ve always been independent until this happened.
                      Now they’re prescribing anti- depressants.


                  • Reb
                    Don’t let your ailment get the best of you.

                    Depression is negative thoughts.

                    I know you got alot more positive thoughts about what you want to do then not do.

                    Just like anything you have done. You figured out how to accomplish it and get it done.

                    Get done what you want done any kind of way you can.

                    It doesn’t matter how long it takes as long as you get it done and make it what you want.


                    • It’s more a lack of drive than feeling negative and I saw the doctor today to discuss any problems I was having with the first med so I start something different tomorrow due to lethargy and bowel issues.
                      I requested something that would make me want to get around more instead of keeping me on the couch.
                      Well see what happens!


            • Chris USA

              Getting them back together is the hard part. I put the tool against a wall and push on the receiver assembly with one hand while slipping the locking piece in place with the other hand. B.B.described a machine in a blog a while back that will do the job. You might need it if you’re trying a stronger spring. Good luck!

              Fido3030


              • Fido3030,

                The “machine” was a spring compressor. He has a nice one. A pipe and bar/pipe clamps do the same thing. You would need the special spring adapter for the bb guns. They are a must for powerful springers though. The TX and LGU you can do off the floor.


                • Chris USA

                  The Blog I was thinking of was “BB gun disassembly” June 23, 2009. Nice illustrations of a typical BB gun. Is there anything airgun BB hasn’t written about!!!
                  Anything I think I figure out for myself I later find he’s written about it six or twelve times!

                  Fido3030



          • Reb,

            It would seem that you would want to (weigh) the chips with a grain scale or something so as not to “over charge” the cylinder??? If you are talking “slivers”,…more, does definitely NOT sound better.


            • Correct!
              And I no longer have an accurate way to weigh something so light so I was gonna have to make an educated guess and be sure to err on the side of caution.
              My decision was made easier when I got to the store and they had changed their policy on how much or little they could sell.
              They wound up selling me 1# for $1.19. I guess with the goods being frozen solid and that 1# it was sufficient to ship from Tx.
              to Il. during the winter.


              • Reb,

                Not sure, but I would think that there would be a ( grain weight -per- tank cc ) ratio/formula.

                I would try it no other way. Probably some other things to take into account as well.


                • I was concerned with burning the seal and was just gonna eyeball the weight, starting with about 5-7 grams.
                  If you really want to get good information on it Wikipedia is the best place I can recommend to get started.


                  • Reb,

                    Thanks,….I like Wiki. Quick and easy. Nothing to try it on though. Just exploring the options,…and the “perils” of airgunning. Stick to #1, and avoid #2. 😉


        • Chris,

          Dry Ice doesn’t melt like most solids. It sublimates — changes directly from a solid to a gas. I think it probably does melt, but an instant after it does, the high vapor pressure of the compound causes it to flash to gas.

          B.B.


          • B.B.,

            Thank you. I did some basic research after the topic came up. I think it would be a good alternative but only if one was to follow all precautions and really know a (weight to cc) ratio. Beyond that, better left alone. I would go PCP with this. But I will (not) without knowing 100% what I am doing. I imagine that solid and trustable info. lacks,…so I guess it’s all talk at this point.


        • Chris,USA
          Dry ice is frozen CO2 ( carbon dioxide) so as it evaporates it gives off CO2 gas and the biggest danger of dry ice is if allowed to melt in an enclosed area with people or animals you will be suffocated by the CO2 gas that builds up and over powers the oxygen in the room.

          I do not think it would be of any benefit in an air gun but have been reading with great interest on another forum about the use of helium in PCPs as it is 3 times as light as air and therefore will move at 3 times the speed of air in a PCP. Hydrogen is even lighter than helium at 3.8 times as light as air but like oxygen is highly flammable ( hint example The Hindenburg ) In theory a PCP that will shoot a 14.3 grain pellet at 900 fps with air when filled with helium will shoot that same pellet with no other changes made at slightly over 1400 fps. The issue with helium is its is a non renewable resource that is a by product of the removal and refining of crude oil from the earth and used to be captured in the process but since the late 60s our govt halted the capture and storage of it so that it just freely floats up into space every day on its own. It is collected by the welding gas suppliers and can be bought in big tanks but from what was stated on the forum it is generally only stored in tank at a pressure of 2000 psi to fill balloons for parties so while in a PCP at 2000 psi it would still propel a pellet much faster than air you cannot fill a 3000 psi gun to full pressure from a tank of it but could fill to 2000 psi and then top up to 3000 psi with air and have a blend that would provide more performance than just air. The thing is when all the helium has floated up out tof the ground into space it will be gone forever or for another 30 million years since it is a product of dinosaur fossil decay and is just not practical or prudent to waste in an air gun for a our pleasure.

          BD



            • Reb
              Been doing ok just having some shoulder issues that make it painful to shoot for long periods of time since the butt stock rests right on a bone spur that limits my shooting time.

              I did shoot today for about 30 minutes today

              BD



                • Reb
                  I have been working on my 300s Match L and Junior along with my grandsons new to him Gen 1 Mrod for him to start FT matches with me.

                  I am always working on one of my air guns improving or tuning it so just trying to keep head down and stay as busy as my body allows.

                  I am always ready to look at your 3120 and see if I can bring it back to life for you and know you are not in a rush so that will work out good as I can not promise a speedy turnaround but will get it brought back to life if it is at all possible so its just when you are ready to send it this way.

                  BD



                    • Reb
                      I cannot say that it might not be torn down and my health cause a unscheduled break to occur as you say but I will nevertheless eventually get it done as only God truly knows what is in store for us.

                      I have had some health issue come up that have slowed me down a bit more hence the absence from the blog but I am still going and slowly getting back up to speed. That’s why I said I cannot promise any set turnaround time but just that it will get done so its your choice if you want to send it to me or not as I will do the best I can to get it fixed in a timely manner.

                      BD


          • BD,

            Thanks for the reply. It sounds as if you have done your homework on the subject. I figured shave off a few weighed grams and drop it in an onboard tank, cap it up and go. Obviously not. I thought it might be a cheap way to do PCP’s. Good to see you post. You always had good tech./tune info.

            Chris


            • Chris,USA
              I have just been reading some on other forums and doing more lurking now than [posting as my time seems to be evaporating faster than it used to in the past several months. I guess its a result of daylight savings and mental alertness since for me when it gets dark I seem to go into shutdown mode anymore ( old and grouchy mode ) LOL.

              I have not really done my homework on CO2 as shaving dry ice off into a sealed container may actually give you a cheaper form of CO2 but I highly doubt that it would reach a pressure close to the 900 to 1100 psi that most cartridges and tanks are pressurized to and would likely require filling the sealed tank as full of dry ice as possible just to have it evaporate into 1/4 or less volume of the tank with liquid CO2 at less than 100 to 200 psi. Just my thoughts though so some experimentation may be required to know for sure but just be safe if doing so as I said above you can suffocate from it very easy used in a enclosed space.

              Here is some interesting reading on the subject of helium versus HPA for use in air guns that I found very interesting myself.

              http://www.gatewaytoairguns.org/GTA/index.php?topic=94721.0

              Let me know what you all think.

              BD


      • GF1,

        Only 20 yds.? I was thinking 30 at least. Drive that bb down range fast enough, and it no choice but to go straight forward,…..right? ( or right, or left, or up, or down? ) 😉 I “aim” to find out. Hey,…that was not half bad! 😉


        • Chris USA
          Yes 20 yards. I was being conservative as to what I hope for.

          But maybe overstepping my statement comparing the 499 to a 10 m pellet gun at 20 yards.

          Come on. It’s a bb gun. It’s going to take some heavy do’n to make that 499 shoot like a FWB 300 at 20 yards let alone 30 yards.

          Dont you hate when people doubt.



            • Reb
              That is good news if your RedRyder did that.

              I guess I keep under estimating a bb gun.

              I was a young’n when I had anything to do with them.

              But on the other hand I had a steel storm a while back. But it was just for play’ n. It was fun. But I wasn’t shooting for accuracy though either.

              If somebody can get the bb guns a different name is this day and age all the better.

              Maybe everybody takes them for what they are and they don’t think it’s worth the effort to explore getting more performance out of them.


            • Reb,

              That is good for a Red Ryder. Mine will open up to 1 1/2″ at 24′. The open sights and me do not get along. The peep and globe on the 499 is no problem though. If I have to go magnet on the 499, I will have to poke the bb past the magnet for each load. I would like to avoid that but it may be a go-to final tune to “dial” it back in. Thanks for the reminder.


  12. The more I read the more I can see why my FX Indy is considered the “Holy Grail” of airguns. Always full, always ready with just three pumps for each shot fired….. If it was select fire, I think it would be God’s Airgun ! But then again… He probably wouldn’t need a hand pump anyway…or to use a gun for that mater….. Unless he just wanted to join in on the fun !
    Bob M


  13. This makes me wonder what makes for the best airgun gas and why. Air certainly has accessibility in its favor. But CO2 guns preceded pcps in popularity,so accessibility is not all. Perhaps compressibility is the other factor?

    Gunfun1, as I understand the theory, the laser will have a different relationship to the scope depending on where it is put. The Delta Force trooper says to mount your laser to the side and not underneath the barrel. Why? I suspect it is because your elevation (the more critical parameter for holdover) rather than windage will diverge with distance.

    As to your scenarios. If the laser is zeroed the recommended way at 50 yards, at 80 yards the laser will be high the same amount as the scope, and the same distance to the side as at 50 yards. If the laser is zeroed to converge at 50 yards, at 80 it will have the same elevation as the scope and be offset on the opposite side of the target as the laser is mounted to the barrel.

    I don’t have a laser to hand. But I experimented with my green laser mounted below the barrel of my CZ 75 SP-01. The laser converged with the sights at about 5 feet as zeroed from the factory. Beyond that, the laser climbed rapidly up which is probably why the laser is recommended to be mounted on the side for rifles.

    Matt61


    • Matt61
      Your laser will do the same on the side of the gun or scope. It will only be true to one focal point.

      I was going to add that on to my last reply.

      And then think what happens when the coefficient of the projectile comes in to play. Add that into scope picture and laser pointing.

      And you know here is something to think about which is why we got into this conversation in the beginning. That Delta force guy is probably using his gun on people size targets.

      I’m sure the kill zone is 12″ that he has to fall in when he makes a shot. Scope or laser. So his determined variation is different than what I want. I want to fall in at the most a 3″ kill zone at 50 yards. Well maybe I can push it to 60 yards.

      You see I have a more precise area to hit than the Delta force guy has. If I want my target to be DOA I have to make my sight more precise. So I need to know what that laser does at different distances. And at a smaller target. With the actual point of impacts in relation to where the laser shines.

      And here it is. Air guns. More precise. Hard to get right to be sure the hit counts. How, shoot and see and document however your set up is. There’s no other way.

      And you know with a laser your exposing yourself. What I was always told about a laser was that it showed your opponent that you were on them. In other words if that dot was showing on you that was bad news. And on the the exposing yourself part. Your going to point a perfect straight line to your exact location on lower light situations. In day light yes you will only pin point a spot on your opponent if you have a good enough laser.

      So if we are going to relate lasers to air guns. And then add in how the person will use a air gun. It will be a different scenario than what that Delta force guy will encounter. I’m sure some principals will be the same. But both sides of how the guns are used needs to be taken into consideration.


  14. I worked in industrial gases for over 30 years, so I know a bit about N2 and O2. I’ve seen what happens to certain metals (including aluminum and steel) in high pressure, high purity O2 fires. They can actually become fuel and will burn (oxidize), not just melt. All that’s needed is a little hydrocarbon (oil or grease) and some energy (striking objects, like valves) and an ignition can occur – perfect conditions in an airgun. The damage to the Fire 201 9mm likely happened in seconds or less, not over the course of a long time. As mentioned elsewhere here, you should NEVER use O2 in a PCP or any other airgun. If something isn’t specifically designed (and cleaned) for O2 service, don’t use it for that.

    In theory and practice, N2 should work fine in a PCP, but that doesn’t mean there aren’t safety issues. Most people don’t realize how much energy is stored in 100 psig gas, let alone 3000 psig. Now go to 6000 psig. Just search for gas cylinder failures to get an idea.


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