.22-caliber Lightweight Disco Double: Part 1

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

You tell me that you enjoy the longer reports that pick apart certain guns and analyze them in great depth. You insist that I explain the technical terms and sometimes also the terms that are specific to shooting. We have a wide spectrum of reader experience in the shooting sports on this blog; so when I write about something, I have to keep that foremost in mind. I try not to jargonize or use insider language, although I’m sure that I do from time to time.

Today we begin what will undoubtedly become a huge report. I think you will enjoy it, but I am asking for your help in managing the questions and comments that will undoubtedly result. So, sit back and pour a fresh cup of coffee or tea, for I think this trip is going to be fun for all of us!

The detailed photos in today’s report are provided by Lloyd Sikes. My thanks to him for all his work.

The 2013 Roanoke airgun show was a poignant one for me. It was the first airgun show in more than a decade where my buddy Mac was not with me. He passed away on May 5, 2013, and I stopped going to events for several months afterward. Roanoke was my first outing since his passing.

I’ve already reported on the show and don’t need to go over that ground again, but one thing that happened there does need to be mentioned. While I was at my table, a man walked up with a Benjamin Discovery in his hand and told me he had bought it from me the previous year. I recognized the rifle as one Mac had sold (we were both at the same table), and I mentioned that to him. I could see in his eyes, however, that he was very concerned with the status of this gun right now!

He had shot the gun for about a year but really hadn’t used it that much. He said that it now had a slow leak that needed to be repaired and had brought it to the show to get his money back. I looked at the rifle and saw that it was in fine shape, and he had the hand pump that came with it but not the box. I fully intended to buy it back from him just because that’s what Mac would’ve done. So, we struck a deal, and the Discovery became mine.

Benjamin Discovery
I bought back Mac’s Benjamin Discovery at the Roanoke airgun show.

It may surprise you to learn that I have never owned an actual Benjamin Discovery! When Crosman and I were developing the rifle in 2007, I tested two prototypes that were Discoveries in every way, but they were not production guns. They were Crosman 2260s that were converted to Discovery specifications. I’d helped develop the Discovery 6 years earlier, but I never actually owned one before now. And, I had a plan for this one!

At the same show, Lloyd Sikes, the owner of Airgun Lab, was set up on the other side of the room. For those of you who don’t know him, Lloyd is the man who invented the technology that became the Benjamin Rogue. But Lloyd is now taking Benjamin Discoveries and adding an additional air tube to double their air reservoir capacity. Mostly, he sells kits of parts to people who want to do the work themselves — it’s easy enough for most people. But he’s also building a few very special rifles from the ground up. For over a year, I’d wanted to test something Lloyd was building, and this Benjamin Discovery seemed the ideal subject!

I walked over to Lloyd’s table and had a chat with him. As fate would have it, he was working on something brand new. He had just started experimenting with what he calls a Disco Double with both reservoir tubes made from aluminum rather than steel. The result is a gun that is nearly as light as the original Benjamin Discovery! When I picked up the prototype gun he had on his table, I couldn’t believe it. It was so light! I wanted one just like it.

Lloyd and I had several conversations at the show, and I left my brand new Discovery with him to build a lightweight Disco Double. I learned that what Lloyd makes is not just one simple product. There are so many changes that can be made in the process of modifying the rifle that a lot of decisions have to be made. We made those decisions both at that airgun show and in emails as time passed. But the original idea of a lightweight Disco Double with dual aluminum tubes remained the core plan.

When I returned from the SHOT show last week and my mail was delivered, there was a box from Lloyd! My lightweight Disco Double had arrived!

This report is going to be about the Disco Double that Lloyd built for me. If you want to know more about the basic Benjamin Discovery air rifle, read these reports.

The rifle
The Benjamin Discovery is a basic precharged pneumatic air rifle that was built to sell at a very low price. The original concept was that the gun would come packaged with a high-pressure hand pump; and because the gun had a maximum fill pressure of 2000 psi, the hand pump would be very easy to operate. When I tested the preproduction guns in both .177 and .22 calibers, each was able to produce 10-shot groups smaller than 1 inch at 50 yards. At the Discovery’s low price, this was incredible performance.

Mac had purchased one of the original 4000 rifles that were made during the first year of production. These are unique because they have genuine walnut stocks that had been made for a special 2260 rifle that was never built. After the supply of these walnut stocks was exhausted, the company changed to beech wood, which is in keeping with the low cost of the gun.

The Disco Double lighweight
The rifle Lloyd built for me has two aluminum air reservoir tubes. In conventional Disco Double conversions, the kit contains either one chrome moly steel or one high-strength aluminum tube that gets added to the rifle’s existing steel tube for greater air capacity, but Lloyd made my rifle with dual aluminum tubes — the first of its type! The No. 1 purpose of this design is weight reduction, and secondarily it increases the air capacity for more shots.

The original base rifle in factory trim weighed 5 lbs., 7 oz. The original air capacity was 130cc. The rifle as now modified weighs 5 lbs., 8 oz. and has an air capacity of 199cc. That’s 53 percent more air. The air capacity has not doubled because the aluminum tube wall thickness is greater (than steel) to provide the necessary strength. So, the tradeoff with this conversion is lighter weight (than an all-steel conversion) for a little less total air, though the air capacity is still boosted greatly.

Benjamin Discovery Disco Double tube comparison
The steel tube (bottom) has thinner walls than the aluminum tube, yet the aluminum tube is still lighter.

Benjamin Discovery Disco Double assembly comparison
Here’s a comparison of the original Discovery air tube assembly (above) with the 2 aluminum air tubes of the lightweight Disco Double. The rifle’s barrel is at the top.

Benjamin Discovery Disco Double lightweight assembly
This is the completed lightweight Disco Double, minus the stock. The tubes have been finished in black to match the barrel. The original Discovery trigger is still attached to this rifle, but will be exchanged for a Marauder trigger.

I want to point out that Lloyd is building his guns with a safety reserve of well over 4 to 1. In other words, the guns are rated for well above 4 times the air pressure at which they’re working. Well above!

Trigger
A normal Disco Double will have a Discovery trigger. Perhaps you’ve read about this trigger in your research on the internet. It’s functional, but it’s certainly not a fine trigger. I can use it without any problems; but if I had my choice, I’d like something better. Well, this time, I did have a choice; so I had Lloyd install a Marauder trigger on the rifle he made. He then had to find a triggerguard because the guard on the Discovery would not have worked.

Testing
Lloyd did an enormous amount of testing of my gun since it was the first of its kind to be built. And he has supplied me with the test data, so I have at my fingertips a whole library of velocities, pellets, fill pressures and some other things I will mention in a moment. If only all the guns I reported on had this kind of data at the start! But Lloyd is a very careful engineer, and I’ve come to know that he documents his work quite well.

Interesting background
Where did Lloyd get the idea for the Disco Double? Is the Benjamin Discovery somehow deficient in air capacity? Not really. But Lloyd was building a special .25-caliber conversion of the rifle for a customer, and it ran out of air very fast. The double air tubes were put there to make that big .25 a workable solution. And, after seeing what those tubes added to the rifle, Lloyd naturally expanded his conversions to the basic rifle, and the Disco Double was born!

The main goals of Lloyd’s kit are:

1. Safely add additional air capacity for more shots.

2. Restore the shot count after making power increases.

3. Maintain the light weight of the Discovery.

4. Provide a kit that can be installed by any airgunner who routinely works on his own airguns.

My rifle
Lloyd and I agreed that it would be best to be able to preserve the original rifle, so if I ever wanted to put it back the way it came, I could. So, the factory walnut stock wasn’t touched. To fit the new double tubes, that stock would have to be routed out. Instead, the factory stock was returned to me as it came, and Lloyd is having a new beech stock made for me by his friend Norm. When that stock arrives, I’ll mount it and return the walnut stock to Norm, who has loaned it to me for photos and to get started with my testing.

Lloyd also produced an upgraded striker spring to give the new rifle more power. Of course, it does reduce the total number of shots; but since the air capacity has been expanded, you don’t notice the reduction over the factory rifle. Lloyd has also provided me with the test data for this performance part.

Benjamin Discovery Disco Double lightweight
My completed Disco Double rifle sits in a beautiful borrowed walnut stock. The Marauder trigger and new triggerguard have now been installed.

Cost
A kit of parts to make your Discovery into a Disco Double costs $165 as of the date of this publication. What you see here will cost $250 in a kit of parts. The aluminum tubes are much more expensive, and I also don’t believe the Marauder trigger has been included in that price.

This first report has been a long one, and we’ve only just begun to see this rifle. The next report will also have a lot more of the background development information, along with some velocity testing.

Oh, I guess I should tell you that this is a .22! And you can forget the serial number because this one stays with me.

90 Responses to “.22-caliber Lightweight Disco Double: Part 1”

  • klentz Says:

    Mac is smiling.

    Had a wonderful conversation with him when I was at Roanoke about conversions and sleeving barrels. Mac was not only a shooter but he knew a lot about many guns. Never thought I would meet someone of his caliber at an airgun show.

    I’ll be following this series very closely and with great interest. Thanks.

    Kevin

  • john Says:

    I would like to think Mac is getting a big kick out of this.

    BB, regarding the 4-to-1 safety factor, I would be interested to know what safety factor is typical of the current establishment pcp industry.

    And, yes, insider jargon is a constant hindrance for newbies like me in this hobby.

    john

    • B.B. Pelletier Says:

      John,

      That’s why I don’t call them M-Rods, P-Rods or Discos. It’s extra work to spell out the full names, but if I don’t, they become unsearchable for the person who doesn’t know what we are talking about.

      This blog must always be the place where you can learn things without feeling left out of the conversation.

      B.B.

      • B.B. Pelletier Says:

        John,

        I didn’t answer your other question. Most reputable manufacturers use a 4-1 ratio for safety. I have seen hobby builders get by with 2 to 1 and a few times I have seen a 1 to 1 margin. When I see that I never stand too close to the gun!

        And example of a 1 to 1 ratio would be a Farco Air Shotgun converted to run on air at 3,000 psi. Not only is the brass reservoir at its limit, we have no way of knowing the quality of the Philippine brass tubing, nor the strength of the threads in the caps on either ends of the tube! I have sen a big bore gun that was made that way.

        B.B.

      • Gunfun1 Says:

        I have been trying to break myself from that habit. I use to be real bad about it. But I’m slowly reforming myself. And I’m serious its a hard habit for me to break. But I will try. So don’t holler at me to loud if I throw one in from time to time. Ok.

      • Matt61 Says:

        Good man. I hate acronyms. And I think it may fairly be said that as acronyms proliferate, the brain turns off and everything goes downhill. Someone in a note just referred me to an LMS. What is that? A Learning Management System. Oh. And someone else was telling me about the SC. That would be Steering Committee…

        Matt61

        • B.B. Pelletier Says:

          Matt,

          Sometimes acronyms are both necessary and safe. For example, when I give an artillery fire mission I’ll say Willie Pete instead of White Phosphorous. It is really more slang that acronym, but when the FDC (fire direction center) questions my command, it’s considered good form for them to to say “Whisky Tango Foxtrot?” rather than what’s actually on their mind. ;)

          B.B.

  • Errol Says:

    B.B.

    What a project Sir. You are so lucky to have such good and brilliant friends. Just shows the almost endless possibilities with mods. with the correct gun and of course being expert on the subject.

    Errol

    • B.B. Pelletier Says:

      Errol,

      Thank you for your kind words. I will admit that I know more about airgun than I used to, but I am no expert. I still have so much to learn. This blog and you readers are my school.

      B.B.

  • PeteZ Says:

    I exchanged a few emails with Mac a couple of years back, just before I fell ill which suspended my interest in shooting and ability to aim reliably. He was a fine gentleman who went to pretty fair lengths to help a relative newcomer. I wondered a bit why you hadn’t mentioned him lately.

    Lloyd’s Disco conversion sounds great! And the technology has other uses too? I’ll just give you one, the one that I would probably buy in a heartbeat. The air tanks for my Steyr pistol are too damn heavy for this old man to lift and hold the gun straight out. Certainly i can’t do it for
    a sixty round match. If Lloyd could make a tank that would replace my long steel tank, and could get it proof tested so no officious match official would claim it’s past its sell by date, he would have my order.

    There are upper limits on the weight of a ten meter pistol, but I don’t think there are any lower limits.

    PeteZ

    • B.B. Pelletier Says:

      Pete,

      I have no doubt that Lloyd could make such a tank, but it would never be officially approved. Approval is based on the company’s records-keeping and it is difficult for a new company to get recognized. But modifications are almost unheard of in this context.

      To give you an equivalent situation, it would be like a German automobile deviating from its design spec and then trying to pass the test at the local TUV. It would never pass!

      B.B.

    • Matt61 Says:

      PeteZ, to answer your question, Bartitsu was a martial arts style developed around the turn of the 20th century from diverse cultural influences. Prior to that the French had developed a style called Savate from obscure sources. It was distinguished by kicking, like the Asian martial arts, although it was quite comprehensive and involved weapons (including the cane for gentlemen walking abroad). Rather than punching, the hand techniques involved slapping!? One reason Savate is not so well-known now is that a whole generation of French Savateurs was wiped out by WWI. The English, meanwhile, had developed their own boxing tradition. In the much anticipated match-up of the ages in the late 19th century between the English boxers and the French “kickers,” the British triumphed, punching their way to victory. But this did not prove to be the end but the beginning as both sides took stock. The French decided to incorporate punching. The British decided there was something to kicking. So a type of kickboxing evolved. Meanwhile with the opening of Japan, it was only a matter of time before Jiu-Jitsu (the original samurai art from which Judo is derived) was imported to England with its far-flung empire. The throwing and locking techniques of this style had no real counterpart in extant fighting styles, so someone had the bright idea of adding them to kickboxing and Bartitsu was born.

      It makes sense that Holmes as a brilliant and knowledgeable person would have picked this up, but one doesn’t associate it with his cerebral style. In my first reading of Holmes as a kid, this side of him completely eluded me.

      Bartitsu as an official style did not last long because of a falling out between its founders. But the resynthesizing of styles goes on today as it has throughout history.

      Glad you’re feeling better.

      Matt61

      • Fred DPRoNJ Says:

        Oh, man. Slapping, punching, kicking and then getting the French involved – it’s all I can do not to make a really derogatory comment and bring the high class of this blog down to neanderthal levels. Thank goodness there is no scratching involved (LOL).

        What many who have never read Edgar Rice Borroughs, the author of the Tarzan novels, might not know is that his Tarzan was a gentleman of English origin who just happened to live in a tree. Johnny W.’s portrayal is technically not correct. But his movies were great and speaking of slapping, punching, kicking,spitting and whatnot, Cheeta was wonderful, too. Omgawa.

        Fred DPRoNJ

        • B.B. Pelletier Says:

          Fred,

          Oh, brother! Do I have a surprise for you regarding Edgar Rice Burroughs.

          On Monday.

          B.B.

        • Matt61 Says:

          Well, I’m consumed with curiosity on your point about the French, but out of respect for the blog I will forebear asking… But take care not to undestimate Savate in its fullest expression outside of the ring. You might find yourself in the position of some East End Londoners at the turn of the 20th century who thought they would waylay a seemingly effete French gentleman with a walking stick. Whamo with his cane and some exotic kicks, and they were among the street refuse.

          Yes, Tarzan’s history is very interesting. Even before learning about his English heritage, Burroughs had Tarzan teaching himself to read from materials from a shipwreck so that he can communicate with the safari that finds him. It’s essentially a Victorian novel about how your Anglo-Saxon will dominate any kind of circumstances that he finds himself in. Anyway, the novels are a great read, and Tarzan can really kick butt, even more than the Weismuller movies. In Paris, he wipes out a room full of a dozen French policemen then jumps out of a window with a girl on his back who says, “You are so strong and so active.” :-)

          Matt61

        • Matt61 Says:

          Continuing my cultural tour, last night I finished watching a movie from 1980 called Night of the Juggler. This was particularly gratifying since I had only been able to watch tantalizing parts through some HBO deal over 30 years ago. I thought it was gone forever and have only been able to see the whole thing now through the good offices of the internet and YouTube. It is a police/psycho movie of a type that seems to have been common in that era. Anyway, the police are almost comically underarmed with their revolvers. They would look severely out of place today as shown in a movie like Heat (which I plan to watch tonight). There, the criminals are running around with AR-15s on full-auto and duffel bags full of magazines. This enables them to shoot their way right through a police roadblock reducing all of the police cars to twisted junk in the process (in quite a display of power by the 5.56 cartridge).

          But notwithstanding the lack of firepower, there is a real sense of…toughness about the people in the 1980 film. It could be because the film focuses on the crummiest parts of New York City which probably have not changed that much. Or it could be because of the shabbier production quality of the film. But this quality seems to transcend the acting and the set and reflect part of some ambient culture. The people look tough. They talk tough. It’s in everything they say and the way they move. I’m still inclined to dismiss this as a perception except for a comment I read that the military has had to adjust its standards for the physically flabby internet generation. Even the Marine Corps has had to make things easier to meet recruiting goals. One of the trainers interviewed said that you began to see the change in the 80s and 90s and it has only accelerated. He remembered the 70s as a time when you saw the last of a really “hard” generation. With physical toughness goes mental toughness, so while we have become better-armed, the fighting spirit may have gone down. And the fact is that post WWII America was still a fairly comfortable place (except for the dregs of New York City) so you have to wonder what people were like before.

          Matt61

      • Gunfun1 Says:

        Matt61

        My wife’s older brother teaches Tae Kwan Do. I have done some training along with both of my daughters. So that was interesting to me what you just posted. I always wondered how kick boxing evolved. That was a good read for me.

        • Matt61 Says:

          Glad you liked it. Do you have a theory on why Tae Kwon Do is the world’s most popular martial art? One theory is it’s importation to America and the observation that Americans love to kick. Hm, well, here’s one that doesn’t. (Although it is a much more fun workout for the core than crunches.) Note well, that the Savate kicks are technically from a different tradition than Tae Kwon Do. However, there may be connection after all. The question is how did the French develop a high kicking tradition that is fairly distinctive in Western martial arts? One theory is that they picked this up as part of their colonization of the Far East. The French flair gravitated towards high kicks from the Asian styles. Further evidence is that more traditional forms of Savate involved placing your hand on the ground to steady yourself for some of the more acrobatic kicks–a good idea to keep yourself from landing on your butt, but also, it is supposed, a good idea for sailors fighting on board a rocking and rolling ship. And, as further evidence for the theory, Savate seems to have been popular among sailors (who like to fight) and who are well-traveled. The international port of Marseille was a big center of Savate…

          Matt61

          • Gunfun1 Says:

            Matt61
            What I’m going to say kind of goes along with your comment about the 70′s generation. And the Tea Kwan Do.

            I guess to start with I was a teenager in the 70′s and there was alot going on then. It may sound crazy but Friday nights after a long, long 5 days of school us kids were ready for some excitement. And here is the crazy part. Fighting was pretty common on a Friday night. We lived in the country/the sticks if you will and we would go into town. Kids from all the surrounding areas would be there. It was the only place with movies and things to do. And remember that was the Muscle car era. So all the races would get started there. So then came the racing. Then after the races things would come up if you know what I mean.

            One of the my friends that lived in our neighbor hood was from Thailand and he could fight no if and or buts about it. I seriously saw somebody come up to him and get in his face and started giving him Sh–t. He was about 6 or so inches from my buddy’s face and in a blink of a eye my buddy hit him up side the the right side of his head and the guy was on the ground and out. I know because I was standing on the left side of my buddy and saw his leg come flying past me as the guy was hitting the ground. Then another time he knocked the heck out of guy with his shoe. We all use to wear those hard sole shoes with about a inch heal on them. And I’m sorry to say it was kind of funny when he bent over and took his shoe off and grabbed it by the toe of the shoe and started whopping him.

            A few more little incidences happened but after that nobody messed with him.

            And on another part of the story to go with this is my dad was in the Korean war and he told me about the way they would fight. And my buddy was over at the house pretty much and he would try(notice I say try) to teach me some of the moves. My dad would watch us and always commented that I would be smart to learn whatever I could about that type of fighting.

            Then I use to hunt with my wife’s older brother before I started dating her. Well that was round 2 he was into Tea Kwan Do. So I kind of got into it a little more. But not ever 100% serious about it.

            So I really haven’t been fully committed and now I’m in my early 50′s and the bones don’t move like they use to so I’m not as active in it as I use to be. But my daughters have been involved in it though so that keeps me interested. They bug me to do some moves with them.

            But I will say that I do try to do stretches and I do still lift weights. And I will say the weight lifting does help with my free hand shooting.

            Oh and yes both of my daughters know these stories about me when I was young. So I think that kind of motivates them to learn about the Tea Kwan Do and the values they teach.

      • Mike Says:

        Bruce Lee — ‘Absorb what is useful, discard what is useless and add what is specifically your own’.

        Mike

      • Michael Says:

        Uh, wearing SHOES, not “shows.”

        Michael

  • Gunfun1 Says:

    I suppose it still uses the male Foster fitting for refilling the gun?

    Do you have to fill both tubes separately or does it transfer air from one tube to the other so you only have to fill once for both tubes?

    • B.B. Pelletier Says:

      GF1,

      There is one inlet for the air which fills both tubes. If it didn’t work that way, the rifle wouldn’t be able to use the air from both tubes unless the shooter manually switched them at some point.

      B.B.

  • Gunfun1 Says:

    I also wanted to mention this.

    If you look at the 4th picture down and take away the double tube (in other words a Discovery in its original form). And put a Marauder pistol grip trigger assembly or a 1377 pistol trigger grip assembly with a Crosman 1399 custom stock on the tube and leave the wood stock off.

    That is the way I have one of my Disco’s setup and one of my Marauder rifles set up. Then you don’t have the extra weight and the bulky filling of the wood stock. It feels like your holding a pool stick in your hand when your shooting. And obviously it lighter without the stock.

    So that brings me to this question. Can I purchase the double air tube only and add my stuff from the Discovery that I just talked about?

    Or does the double air tube come with the gage port and gage already installed and the air transfer valve in the tube also? And all I have to do is put my barrel and pistol trigger assembly on the double air tube?

    • RidgeRunner Says:

      GF1,

      The tubes are connected directly together, so they both fill at the same time.

      Go here and start drooling. http://www.airgunlab.com/

    • B.B. Pelletier Says:

      GF1,

      I think Lloyd needs to answer this question. He sells his parts as kits, but he might be willing to sell parts from them — I just don’t know.

      B.B.

    • Lloyd Sikes Says:

      GF1,
      I think what you are asking for is the standard kit. Tom’s Discovery is special because most of the original top steel tube has been replaced with aluminum, but normally, you keep all of your original items intact, and the new lower tube is attached by special fittings at the front end.
      And yes, I will sell individual parts and do a little customization on occasion.
      Lloyd-ss

      • Gunfun1 Says:

        Lloyd
        I did go to your website that RidgeRunner posted and looked at the different things you have.

        And yes the standard Discovery kit would be what I’m looking for. And I forgot to look. How much does it cost? And do you make them to order or do you have them ready to ship?

        I hope I’m not getting a head of things here but I would like to know. Sounds like I want to try one of your kits on my Discovery that has the 1377 pistol trigger assembly with the 1399 stock.

  • RidgeRunner Says:

    I really like that trigger guard. It is very similar to what I did with my Edge trigger guard.

    I have been giving serious consideration to buying a Marauder Pistol and doing his double conversion to it.

    It is incredible just how far you can modify this air rifle. Basically, you can replace almost every single part to the point that you have a totally different rifle. I guess if you are determined to own only one PCP rifle that is good, but at what point do you say “Why don’t I just buy another rifle?”

    I missed talking to Mac at the Roanoke show.

  • RB Says:

    B.B.,

    I would like to see an airgun show. Is there a listing of shows and dates?

    I’ve only had my Discovery/pump combination for a few weeks. It’s my first PCP, and we’re off to a good start. I plan to shoot the unmodified rifle for awhile, but a lightweight Double Disco and improved trigger is in my future. Also, I’m interested in decreasing it’s power to increase the shot count per charge. 12fpe would be enough power for me. And quieter is always better.

    I have several firearms given to me by close friends. When we were teenagers, Craig and I used to shoot his Colt Woodsman. He gave it to me 25 years ago, and passed away not long after. It brings back great memories of our youth and times spent together. I look forward to reading more about Mac’s Double Disco.

    RB

    • B.B. Pelletier Says:

      RB,

      You are the ideal reader to get a lot from this series. Learn your Discovery and by the time I have done several more reports you will know what it is that works best for you.

      Speaking of quiet, Lloyd did send me a TKO muzzle brake to quiet the report of the rifle, and I will be testing it for you.

      B.B.

    • B.B. Pelletier Says:

      RB,

      I forgot about that show date list. Yes, it is possible to post and I will work on it.

      B.B.

  • Lloyd Sikes Says:

    B.B.
    Thanks for giving me the opportunity to work on Mac’s Discovery, and thank you for sharing it here in the blog. I always enjoyed talking with Mac, in particular about his photography work. He was a fine gentleman.
    Lloyd-ss

  • /Dave Says:

    Nice job, Lloyd!

    BB,

    You’ll need to remove that top tube’s front cap to use the TKO brake. That’s where the Foster fitting is on my normal Discovery so I just leave it off mine since I didn’t send it to get modified. TKO Mike will make or modify the cap on request.

    /Dave

    • B.B. Pelletier Says:

      /Dave,

      That’s good to know. Thanks!

      B.B.

      • Gunfun1 Says:

        If I remember right he doesn’t charge for that. It has been a while. You just send yours to him then he sends it back modified. But dont quote me on that. You will need to ask if that is still true.

        Mike has also made me custom breaks in the past but I don’t know if he still does that. Here is his website. I hope it was ok to post it.

        http://www.tko22.com/

  • edlee Says:

    I think it quite fitting,, that you now own one of the earlier PCP air rifles,, that you had a great deal to do with designing,,, AND that once belonged to a close friend,, now passed. I have no doubt that this piece will have a place on honor in your collection,, and that selling or trading it will ,, quite simply,, not be an option. How fortunate for you,, for it to have “had a leak”.
    Ed

  • Matt61 Says:

    B.B. have never owned a Discovery? Well, it’s time that was rectified. This reminds me of how Colonel John C. Boyd of the U.S. Air Force, who designed the F-16 fighter plane, was never allowed to fly it. This is a great way to remember Mac as well. I would hang on to this rifle. Nice to hear that Lloyd is being so productive. I was wondering what he was up to after an achievement like the Rogue. Double the air capacity with no cost in weight or redesign is quite something and bound to keep the Discovery competitive for some time.

    Titus, yes how interesting that the Johnny Weismuller Tarzan has never been surpassed even with modern movie-making techniques. In part, I think it’s because he swings through the trees much faster than anyone else! I’m interested too in his swimming achievements. Despite being one of the greatest swimmers of all time who was never beaten in a race and one of the very few who won two gold medals in the 100 yard freestyle in consecutive Olympics, his times now would barely get him into the Olympic Trials today. This says more about the development of technique and training than about him since apparently swimmers in that era swam with their heads poking up out of the water rather than turning to the side to breath. In any case, even in the era before weight training, he is quite a physical specimen running around in his loincloth. And it is to this and his general caveman persona that I attribute his enduring fame. He is pretty rough with Jane and other women on safari, grunting, shoving them around and hauling them out of his grass shack by their ankles. In one he even makes Jane play Wheelbarrow with her walking on her hands as he holds up her legs from behind!? She doesn’t seem to mind. So while a little light in production quality, his movies are great in their caveman routine which apparently never goes out of style for movie audiences.

    Matt61

    • JTinAL Says:

      If you think Johnny Weismuller was a caveman type you should look up
      the 1st (I think) big screen Tarzan,Elmo Lincoln played him in 1918.
      Too funny to see it now :)
      My older bro is a collector of Tarzan movies and books so I’ve been able to see
      most of the American and quite a few foreign Tarzan films.
      Also interesting is that some of those who played Tarzan were also bad guys
      in other Tarzan movies.For instance Frank Merril was Tarzan but then later
      was a villain when Gordan Scott was Tarzan.A lot of the characters in the movies
      also came back in the TV series with Ron Ely (of Doc Savage fame),Jack Elam being one of the most
      famous that I can remember.
      Mike Henry was one of the few who played Tarzan and then went on to play different types
      of roles,he was in several westerns as well as the Smokey and the Bandit series.He played Jr to Jackie Gleasons Sheriff Buford T. Justice.(yes I’ve spent way too much time watching TV lol)
      As much as I liked the Tarzan shows,the original books by Burroughs were much much better IMO.

      • Michael Says:

        Hey now, my grandfather-in-law was friends with Johnny Weissmuller (as well as Jane Addams). ;^)

        He also personally knew Al Capone.

  • Tin Can Man Says:

    BB,This is tantalizing.Looks like it would be light weight,quite powerful,accurate and even good looking.And shot count too.
    I’m glad to see people concerned about gun weight.It seems that mostly by the time we get a rifle that has good power and accuracy it weighs a lot.Then when we put a good scope on it that does it justice for it’s capability,we make it all the heavier.Then off hand shooting it very long gets tiring fast.
    You have told us how some gun weight is important and an aid in accuracy,but I don’t remember anyone drawing a line of reasonability (is that a word?).I have rifles that weigh up to about 11pounds and that’s ok for a long range supported shot but now I want a light weight, capable, off hand shooter for 10 to 50 yards and sometimes out to 75 yards for non live targets.
    You are right;this is fun already.-Tin Can Man-

  • Toby T. Says:

    So… the Marauder trigger assembly bolts right onto the Discovery or have I not read something that tells me otherwise? I’m kinda lazy about finding the answer I am looking for sometimes.

  • Gunfun1 Says:

    This is a little different question. And because of different reasons may not be able to be answered.

    Multiple things are linked together with this question.

    First off the computer controlled valve system that the Rogue uses is way cool stuff. But here is what I would like to know.

    If that valve system was used with the Double Disco ( Double tube Discovery). Could a lower pressure (800 psi/Pounds per Square Inch) Pre-Charged Pneumatic/PCP gun be made?

    I would think you could use the computer and valve system to make the duration of the air charge longer to use that lower 800 psi fill pressure to make the shot have a reasonable fps/Feet Per Second and shot count. Or even a lower fill pressure if you think about it.

    Wouldn’t that be the equivalent of a modern day out side lock rifle like Gary Barnes made if it had the longer barrel also?

    • twotalon Says:

      GF1

      How about if you define what you mean by “reasonable velocity and shot count “? Put some numbers on it.

      twotalon

    • Lloyd Sikes Says:

      GF1,
      If you think about what people have achieved with CO2 guns, that is about the maximum velocity/power you will be able to achieve with 800 psi air. The limitation is physics. F = m x a. Or, Acceleration equals Force divided by Mass. The force is the psi x the bore area, and the mass is the mass of the pellet PLUS the column of air that also must accelerate through the barrel behind the pellet. So you have a finite limit on the acceleration and therefore the velocity, but as you said, the longer the barrel, the more time for the pellet to accelerate. Given that, it’s not too difficult to calculate how long the valve needs to stay open, and to make electronics to control it. But the trick is: can you make a mechanical valve to turn the air on and off that has adequate repeatability? Daystate’s CDT valve uses a somewhat direct acting electric solenoid that varies the dwell according to the gun’s reservoir pressure to maintain a consistent velocity. It works well. However, the direct acting solenoids are limited in their power capability. It is easy to open the valve, but extremely difficult to close it fast enough (within a few milli-seconds) and consistently enough (repeatability of 20 to 50 micro-seconds). The technology in the Rogue uses a totally different air operated system to open and shut the main high pressure air valve and is very suitable for power levels well above 100 fpe. That technology has not yet been fully exploited.
      With either of those two types of technology, you can (theoretically) vary the valve open time (dwell) and use an un-regulated air supply and shoot it with constant velocity from full reservoir pressure all the way down to a defined low pressure consistent with the desired velocity.
      Sorry for the long winded answer to your question, and I am not sure if I even answered it.
      Lloyd-ss

      • Gunfun1 Says:

        Lloyd
        So could the system from the Rogue be used to control shot with a lower fill pressure with a smaller caliber and slower feet per second. Like the example I just gave twotalon.

        800psi at 600fps with a .22 cal. pellet. and get maybe 15 shots using the Double Discovery tubes.

        I guess the part that I didn’t quite understand is about the higher foot pounds of energy that the Rogue will control. I think what your saying is the system from the Rogue would have a harder time controlling the lower pressure shot?

        And no your answer wasn’t long winded. And sorry that I’m a pain in the butt.

        But what better person to ask if you developed the Rogue system. What I would love to see is a computer controlled system that I could punch numbers in and control the fps and shot count and such on a lower scale small caliber lower fps PCP gun. Like a mini-Rogue if you would.

        • Gunfun1 Says:

          Oh and 800psi doesn’t have to be the fill pressure. It would be just fine using the Discovery’s current fill pressure.

          Maybe I’m thinking wrong. But I thought maybe a lower fill pressure would be easier on the valve system. Not as much pressure so then the valve system wouldn’t have to work as hard.

          • Wulfraed Says:

            Lower source pressure likely translates to an even longer valve time…

            Attack this from the other end… How much residual pressure do you want in the barrel at the moment the pellet leaves the muzzle?

            800PSI using a source of just over 800PSI? The valve will have to remain open the entire firing cycle until the pellet exits.

            800PSI using a 1600PSI source? The valve can close when the pellet is half-way down the barrel — at that point you have 1/2 bore-volume @ 1600, so doubling the volume to the muzzle gives you 800PSI.

            • Gunfun1 Says:

              That’s why I think think the computer controlled valves could come into play after regulating the system pressure down to the 800psi.

        • Lloyd Sikes Says:

          GF1,
          Please let me make a little clarification first. I developed the technology that is used in the Rogue, but Crosman developed the Rogue.
          To your question, you would be able to get many more shots than what you are asking for. There is a low limit on what pressure will actually drive the pellet at 600 or 700 fps, but it is well below 800 psi. The technology that is in the Rogue and in the Daystate electronic systems will both work, but the application has to be right for either of them to make sense economically. And it should be an application that can’t already be done just as well with a more conventional (and less expensive) technology. For instance, what you are asking for might better be handled with a nice built-in regulator. Tune the conventional mechanical PCP valve to shoot 600 fps at 700psi, set the regulator in the gun for 700psi, and fill the reservoir to 2000psi. That will give a nice long, flat shot string at reasonable cost.
          The reason I mentioned the higher FPE (power) applications is because those can be more difficult to control with conventional mechanical systems. For example, being able to shoot a .45 cal from 3500 psi down to 1700 psi with a consistent velocity, and being able to do it using different bullet weights. Without using a regulator. Theory and application are two different things, but it can be done. If you are interested, here is a video of one of my prototypes from a few years ago that more or less demonstrates this. http://youtu.be/Rnf4uvUTx4k
          I hope the link works. You might have to cut and paste it.
          Lloyd-ss

          • klentz Says:

            Mr. Sikes,

            I’ll always remember Tom introducing us to one another at Roanoke because of the introduction of your revolutionary airgun technology that followed soon afterwards.

            You may not remember but he prefaced our introduction with, “Lloyd has invented something that is going to be a game changer in airgun big bores.”

            You’ve certainly done that and more. Your aftermarket offerings for the Discovery are proof.

            It’s hard not to agree when you say, your “technology has not been fully exploited.”

            Your video of 7 shots @ 500++fpe with a 405gr + projectile is proof.

            Please don’t loose any motivation in your endeavors. So many of us are watching and cheering you on.

            Don’t know what your agreement is with Crosman but if funding becomes a problem I would like to help you find sources.

            Kevin

          • Gunfun1 Says:

            Lloyd
            Nice video. I totally like how the feet per second stayed pretty darn consistent. And I do understand when you say a regulator could work just as effectively I guess in relation to cost.

            I guess I’m a person that likes to think when a technology is developed it can be refined or used with a existing technology possibly. So here is my what if question.

            What if you used that lets say 3000psi fill pressure and regulated it down to 800 psi. Then used the electronic valves/mechanisms with the computer to control the air flow to the barrel for the desired duration of time the valve stays open to control the feet per second of the projectile.

            Or am I contradicting myself by trying to get both systems to work together. But then you could have a gun that gets bunches of shots and consistent feet per second through the hole range of available air.

            And thanks for taking the time to answer.

            • Lloyd Sikes Says:

              GF1,
              What you are suggesting will definitely work.
              Lloyd

              • RidgeRunner Says:

                Lloyd,

                Does Crosman have the technology tied up to the point that you cannot do anything with it?

                They messed up with the Rogue. Apparently they went after the big bore and the black rifle crowd at the same time. The initial offering was also too complicated to program for the average bloke like me, and was not powerful and accurate enough for the big bore guys.

                Now that they no longer are producing the Rogue, maybe they will talk with the big bore guys and build something that they would buy. If I had the money, I would buy a Rogue and strip it apart so as to build something a bit more suitable.

              • Gunfun1 Says:

                Lloyd this kind of goes with what RidgeRunner just said.

                First is the technology caught up in the redtape? If not could it be possible for you to build a smaller caliber version using the things we talked about above? Or have it built by somebody like Crosman did with the Rogue?

                And I know we got off subject a bit from the original topic but if a new gun could be produced that excites me.

              • Gunfun1 Says:

                And I have another question about the Double Disco tubes. Its getting thin up here so I will move down.

  • dangerdongle Says:

    I tried a disco double one night back in the day. First one went great, but by the time I got to the second I was so loaded I tripped over my platform boots and knocked myself out. Never even made it though the door.

    Everyone else had a really great time though!

    • Gunfun1 Says:

      dangerdongle I really hate when that happens.

      But what I want to know is how did you know everybody had a great time when you were knocked out? ;)

      Sorry I couldn’t resist. Don’t hate me. :)

  • 103David Says:

    Just as an observation on the divergent thread of weaponless hand-to-hand “exercise,” (a term I use purposely and specifically.) While I deeply respect and admire the various disciplines mentioned, and acknowledge much can be learned in their pursuit, it’s well to remember a real-world confrontation absolutely requires ones opponent be willing to dance the same dance you are.
    Real life will rarely, if ever, offer that option.
    To put it more pointedly, in my…interesting..life I have been graphically educated on the point that the “kick,” as performed by even the most practiced and expert “kicker,” whatever the discipline will result in the “kickee” making the “kicker” eat their own foot.
    Pretty much 99 percent of the time.
    An experienced contender will be happy to tell you, once their feet are off the ground, they irrevocably belong to you.
    It’s always wise to remember the first rule of a gunfight (which is the same rule as a knife-fight, a bar-fight, a sword-fight, a fist-fight, a martial-arts type fight or any other real world…disagreement.
    1.) Try real hard…REALLY HARD, not to get into one.

    • Gunfun1 Says:

      103David
      Your absolutely right. That is something that is part of the teaching. You should always try to not let the fight happen no matter what type of weapon you have including yourself as the weapon. And that is just common knowledge to try to avoid the confrontation.

      That is why I’m glad that most states allow the right to carry. And then if you have additional training all the better. The way I see it. It helps gives a person more of advantage if a circumstance happens. Especially when there is no time to chat if you know what I mean. That is why both of my daughters took some classes. They know they are not supposed to go around bullying but if something is going down they have the right to protect themselves. So with the Tea Kwan Do training that they did have will hopefully help if a situation arises. And it does help this old dad to rest a little easier.

      So I would say training in the martial arts, yoga, weight lifting, stretching all help in some way to keep the body fit. So another benefit.

      • 103David Says:

        Not a single thing I could disagree with and an excellent digest of exactly where the true value of the various disciplines lay. Self-confidence and a sense of inner strength will last a lifetime.

    • Wulfraed Says:

      It’s always wise to remember the first rule of a gunfight (which is the same rule as a knife-fight, a bar-fight, a sword-fight, a fist-fight, a martial-arts type fight or any other real world…disagreement.

      Isn’t the first rule for a knife fight “Don’t bring a knife to a gun fight”?

      • 103David Says:

        Actually, no.
        And it’s a common and facile misconception the inexperienced and misinformed often have about this sort of thing. The truth of the matter is the “rule” that one should always “bring a gun to a gunfight” is not “number one” but rather somewhere down around number seven or eight. The reality is first, one needs to understand exactly what “Wining,” “Losing,” and “Not winning” really mean…
        Waking up in your own bed the next morning is the base-line we’re talking about here, As opposed to waking up in jail or not waking up at all.
        Strategy means avoiding situations where you might get shot, which would mean, “You lose.”
        Tactics means you walk away from a situation and thusly prove you’re smarter than the other guy.
        I could go on, but hopefully you’re getting the idea.
        Tomorrow’s another day and if you didn’t get shot tonight, than all things are possible

  • Gunfun1 Says:

    Lloyd
    This is the question about the Double Disco tubes.

    I don’t know if you want to or if you are allowed to answer this. But looking at the parts when I was checking them out on your web site. To me it looks like most of the parts were made on a vertical and a horizontal CNC machine. Is that true? And do you have your own machine shop or do you have it out sourced?

    Just tell me to shut up if I’m getting to deep but I’m a machinist and the part of making the product interests me too. And again thanks for taking the time to answer all my questions.

    • Lloyd Sikes Says:

      GF1,
      I do all of my own engineering and design work, and build all of my prototypes, including the electronics, and do the testing. I utilize some small, high quality, local CNC houses to make the production parts, but I do the final assembly and testing on everything that goes out the door.
      Lloyd

      • Gunfun1 Says:

        Lloyd
        All I can say is my hat is off to you. Especially on the electronic part. I bet a lot of time and research took place for it all to come together. And probably a lot of head aches also.

        But I can say this. If I had a job doing what you do I would be excited to come to work everyday. And I’m going to go out on a limb here and say I bet you got more up your sleeve. And if you do you got to tell BB so he can report on it for us.

        • Lloyd Sikes Says:

          GF1,
          Thanks for the kind words. I did all the development work in my spare time (that’s a joke these days, isn’t it?) while I was employed as a manufacturing engineer. I retired a year ago but have been busier than ever. The airgun work is a true labor of love. Making something better is always the goal.
          Lloyd

  • Tin Can Man Says:

    lloyd Sikes,I wanted to write you yesterday but felt too foolish.You know BB. doesn’t have the heart to tell us how crazy our questions are sometimes. But in my lifetime I may never get to talk to an engineer like you again.

    You mentioned control and repeatability problems to Gunfun1.I don’t understand how you or Daystate made your control systems.It seems to me that all use some form of in-line linear actuator to control a valve stem against air pressure and return spring resistance(with friction too)Even non electronic systems use hammer mass and springs.Inertia is the enemy of control in all these methods.Getting the mass to move,producing just the right momentum,stopping it’s motion and getting it back in place are just the begging of control troubles.Extreme cold and heat foul spring action,lube action,and alter friction and fit of parts.

    Why not use a cam on a shaft controlled by stepper motor positioning?You could Play with cam shape taking advantage of mechanical advantage with it’s inclined plane,and tailor the let off for a pressured barrel for best efficiency and also projectile velocity.Full or partial open valve conditions could be tailored for duration by the stepper motor under embedded computer control.
    Stepper motors add weight but we get rid of the hammer/solenoid mass.Triggers can be simplified to a contact switch and a blade.Interfacing the gun to the shooter can be reduced to a computer connector and a reliable,decrementing shot counter.No pressure guage,no readout screens,no buttons,less weight.The shooter would use computer software to set up his scenario for velocities,shot count,initial tank pressure,and projectile,download it to the gun and it would always shoot that way till interfaced with computers again.An accurate fill system all that would be needed.
    R&d can be cut for a test gun with electronic control modules already existing even micro-controllers,and the final system using surface mount lsi circuitry except for the heavier transistor switching.
    While this is nuts for a little pellet gun and who could afford one just look at 1974 discrete component electronics technology and compare that to today’s’ surface mount capabilities and realize tat it was people like you that got us there.-Tin Can Man-

    • Lloyd Sikes Says:

      TCM,
      Questions are always good and more than one person will learn from the answer. It’s usually a matter of who has the guts to ask it first.
      You’ve made some good points. Nowadays, the electronic controls are limited only by our imagination, and as always, the mechanical stuff is what takes the real head scratching. A lot of the potential problem areas can be designed out of a system and replaced with less trouble prone solutions. Your cam Idea is good, a kind of desmodromic system that eliminates hammers and springs. My prototypes did something like that with one solenoid to open and another one to close. The biasing could be set so that, for example when you had high tank pressure and wanted low velocity, the closing cycle could begin before the open cycle was complete. That could give a very short “partial burst.” Another feature that would be very helpful is an on-board chronograph to provide a feedback loop so that the system isn’t always running open loop. Too bad Hall effect sensors need something magnetic to function. That would be sooo easy. There probably are robust, inexpensive sensors that would do the trick.
      As always, there are many paths to the answer, but most of the paths have problems that cannot be solved (yet) in an economical way.
      You may have already thought through the potential problem areas of your design and have solutions to them. But its a tough road.
      Lloyd

      • Gunfun1 Says:

        I just wanted to throw this comment in there.

        I mess around with drag cars. And learning air flow is part of the trick to make a engine run. And here is the part that relates to the airgun valves and cam design that Tin Can Man brought up.

        The camshaft lobes and the location of the lobe centerlines and the ramp of the lobe all have to do with filling the combustion chamber with the air fuel mix. So that could be a very efficient design on a airgun if the right components could be found and were used. And doesn’t that kind of go back to the outside lock gun that Gary Barns made. But using electronics to control the cams instead of the spring? I would love to see a gun made like that.

      • Tin Can Man Says:

        Lloyd,Funny,I was thinking about that 2 days ago.The metal barrel gets in the way of the sensors.A small pickup coil might pick up tin in a pellet and detect the extra inductance ,but not likely well enough.For something with a shroud;put sensors inside with the baffles and exit wires through near barrel end where pressure is low.I job shadowed for a co. in town that made hair diameter sheathed wiring.Their electronics connected directly into the brain to help Parkinson’s victims.-Tin Can Man-

  • John Says:

    Lloyd and Norm are top notch! I’ll be watching this series intently. :)

  • pellettron2240 Says:

    I’m sorry guys, this conversations of just jitsu and sabate and all this fighting styles are great plus I like to watch old movies too but, wherent we talking about the disco double? Or did I get lost somewhere!

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