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What is a bullpup?

bullpup
This FN_90 PDW is a modern example of a bullpup.

This report covers:

  • Not used for black powder
  • Nelson Lewis combination gun
  • Blew it up
  • Back to today
  • Why bullpups?
  • Reader Mel said,
  • Reader RidgeRunner said,
  • Reader ISCC said,
  • Reader hihihi said,
  • Bullpups today
  • Airguns
  • BUT
  • Triggers
  • Summary

Today we’re going to look at the bullpup rifle design because I sense from the comments that some of you don’t know what they are. From what is said it seems to me some of you think they came from airguns. They did not. Bullpups came from firearms, and you have to go back at least to the late 1940s to see the first ones.

old bullpup
This Winchester model 70 in .257 Roberts caliber is a bullpup from 1954. Look where your cheek sits!

The early bullpups were mostly bolt actions like the one shown above. That meant that your cheek sat on the action where 45,000 to 50,000 psi of pressure was generated with every shot. The bolt action design drove that fact home. 

Not used for black powder

The bullpup design was never used for black powder, as far as I know. You may find black powder bullpups today, but I am talking about the arms that were made in the 19th century and earlier.

I think I know the reason for this. A percussion black powder firearm has a nipple for the percussion cap, so on a bullpup your kisser would be sitting next to a hollow tube behind which is 25,000 psi of pressure on every shot. Trust me — I know because my 1865 combination gun made by Nelson Lewis blew up in my face several years ago! Time for a sidebar.

Nelson Lewis combination gun

Back in 2012 and 2013 I shot my Nelson Lewis combination gun for you several times. I was trying to teach you things about accuracy. But that gun was made around 1865 and in October of 2012 I did something stupid with it. I blew it up! Let’s see.

Nelson Lewis gun
My Nelson Lewis combination gun.

Blew it up

That’s not entirely accurate. What happened is the nipple that accepts the percussion cap was blown out of the barrel and right past my face. When it went, it sheared off the hammer lug that connects the exposed hammer to the sear. I never found the nipple, but the hammer was lying on the shooting bench next to the gun. When my shooting buddy, Otho, asked me if I was okay (he was standing behind me, having a premonition that something bad was about to occur), I answered, “NO” for the first time in my life. Usually, guys will say everything is okay right after they’ve sliced off their thumbs with a circular saw, but this event was so startling that I wasn’t really sure what my condition was. “No” just popped out.

Okay, get ready to criticize and tell me what I did wrong because I haven’t got a clue. Do you remember me telling you that airgunner Mike Reams can make swages to make conical bullets of almost any caliber? I learned that at the 2012 Roanoke airgun show. And do you remember that I wanted him to make a set for the Nelson Lewis gun? Well, what I did this day on the range was called a “proof of concept” test. I loaded a conical bullet in the rifle — partly to confirm the diameter requirements for Mike and partly just to see if the gain twist rifling really would stabilize a conical. But the only conical bullet I had was a 250-grain lead bullet for my 38-55 Ballard, which coincidently has almost the identical size bore as the Nelson Lewis rifle.

I’d been shooting a patched .375-caliber swaged round ball in the rifle up to this point. That ball weighed 80 grains. So, 250 grains would be heavier — about 3 times heavier. What I did was load a proof load into my 160-year-old gun and shoot it. Nothing wrong there, right?

When the gun fired, it recoiled more than usual (no kidding!), but that wasn’t what I noticed. I noticed a jet of fire about a foot long coming out of the nipple hole that had been so recently vacated. Then there was the verbal exchange between me and Otho, and then he cautiously walked around to my front and looked at my head — mostly to see if it was all there.

I’d been wearing shooting glasses, which I always do whenever I shoot a black powder arm (and after this event, when I shoot anything else, too), so my eyes were fine; but above my right eye was a large patch of black powder that embedded itself in my skin. I looked like the “murdering coward Tom Chaney” from the movie True Grit, who coincidentally had a black powder Henry rifle blow up on him. The powder had to be picked out of the skin with tweezers over the next few weeks and there is still some of it in there today, more than 4 months later. But I was okay.

Nelson Lewis combination gun nipple out
The nipple was blown out!

My Nelson Lewis gun, on the other hand, was broken. And, as far as I know, Nelson Lewis doesn’t work on his guns anymore, having been deceased for the past 135 years or so.

Back to today

Okay, I survived that stupident and Otho fixed my rifle for me. I shot it one last time and it now hangs on the wall in my living room. Otho has since passed away and I feel my luck with this gun might have run out. But the point is — what if this had been a bullpup? Instead of a 12-inch long jet of fire coming out in front of my face the jet would have been inside my head. Ouch!

Shop PCP Rifles

Why bullpups?

Bullpups were created to be compact hunting weapons. The military didn’t adopt them for several decades, but when they did they jumped in with both feet. They did it just after going from bolt action to select fire weapons. And therein lies the issue I will discuss in a bit.

The small size of a bullpup makes it ideal for carrying inside vehicles. In the past submachineguns that were smaller for purposes like that were only made in pistol calibers that had limited range. But today’s bullpups can be and are full battle rifles.

Now let’s read what some of out readers think

Reader Mel said,

“Bullpups may be fine if you are a soldier. You get the bore in line with the shoulder (better recoil management) and the large distance between barrel and sight is not an issue because your targets are people sized and may be anywhere along the bullets trajectory bow anyway.

“An airgun has no need for recoil mitigation, and the targets are typically smaller than the distance between bore and line if sight in a bullpup. And you don’t shoot an airgun from inside an IFV or whatever.”

“So my 50 cents on that topic – bullpup designs offer no advantage in the airgun world.”

Reader RidgeRunner said,

“Mel83,Even with inflation, I could only come up with 25 cents.

“The bullpup design in airguns allows for a longer barrel which allows the report to be quieter and allows the air to act upon the projectile longer, thereby increasing velocity.

“There are also those who will argue that a bullpup allows them to maneuver the air rifle in thick brush easier. What do they think they are doing in that thick brush, I do not know.

“The design also appeals to the couch commandos who want their air rifles and air pistols to look like real weapons.”

Reader ISCC said,

“I can tell a bullpup is a great configuation if you are a hunter. My Artemis P15 is easy to point and shoot, easy manouverable, even from tight spaces, like shooting from inside a truck.

Note. This is not a target or benchrest gun, is a 30 FPE hunting gun.Just my 2 Mexican Pesos.”

Reader hihihi said,

“To design a carbine with a long barrel seems like genius to me!

But less so to name it bullpup, ie how close is ‘pup’ to ‘poop’ (or was it inspired by a literal bullpup)?

I like the idea so much that I have tried to overcome my preference for the look of a traditional long arm layout, and this Hatsan Flashpup QE even has nice wood and metal (which I like), yet I think I’m too long in the tooth, ie I failed.”

Bullpups today

Bullpup firearms today are mainly military. And, because they are either semiautomatic or select fire (both semi and full auto), the action is hidden inside a metal receiver. Indeed, many younger gun writers think the problem with bullpups is the fact that they throw their expended cartridges in an inconvenient direction for left-handers. While that is true, shooters are still putting their faces next to an explosion that today ranges upward of 55,000 psi. My Nelson Lewis gun blew up at 25,000 psi. A firearm cartridge explosion today will take off most of the shooter’s head.

Airguns

Ironically enough, airguns come nowhere near those pressures. A pneumatic that’s filled to 3,000 psi probably puts no more than about 1,500 psi into the barrel at any time. That makes airgun bullpups much safer than firearm bullpups. So safety isn’t an issue.

BUT

And this is a big but — do we need them? Well, need often turns out to be a subjective term. But are there real reasons for bullpup airguns? I can think of one for certain — barrel length.

Like black powder arms, pneumatic airguns develop their power with longer barrels. We know from testing that CO2 guns stop increasing velocity somewhere between about 14 and 19 inches of barrel length. The number depends on several things like the caliber, the ambient temperature and the firing valve setup, but we know for a fact that smallbore CO2 guns do not gain velocity with barrels longer than about 20 inches.

On the other hand pneumatics keep increasing in velocity out to just past 30 inches. I have heard the figure 36 inches quoted in the past. Now who, besides the shooter of a Kentucky rifle, wants a barrel as long as 36 inches?  

Well, people who want power want velocity and with a pneumatic a longer barrel is the easiest way to get it. But at some point the rifle becomes cumbersome. Oh, you’ll hear airgun hunters talking about maneuvering through thick brush, but they’re not hunting cape buffalo! Very few squirrels have been known to charge a hunter from concealment and gore him.

But once you understand that fact further discussion is pointless. You either will or will not own a pneumatic with a long barrel. If a long barrel is what you want, a bullpup is one convenient way to get it.

Triggers

My last point will address triggers. On bullpups of all kinds the triggers are notoriously poor. Back in the 1950s and on through the end of the century the bullpup trigger blade was ahead of the sear, so a long bar connected them. That bar flexed, adding travel to the trigger blade, plus the connection joints added both travel and friction. Has that been resolved? Well, the Hatsan Flashpup I’m testing has a decent trigger, so I guess the answer is yes. I doubt a mechanical bullpup trigger will ever rival a great standard action trigger, but they now seem to be capable of getting pretty close. I say capable of, and not that all bullpup triggers are now good, because like everything else it still depends on the manufacturer, how close they can actually get.

Summary

That’s my brief look at bullpup rifles. What did I forget?

79 thoughts on “What is a bullpup?”

  1. “My view of this blog” or “Why I love this blog”

    Dear B.B. and Readership,

    Everyone here shares a love of airguns, which is great, of course.
    Yet what makes this blog pretty unique (in my opinion) is the way people interact here. I’ve seen many other blogs where people can get nasty or mean-spirited with each other. But that’s not the case here, and I think much of the credit for that is the way B.B. and Edith set this up to be a family-friendly blog, and I really like that.

    While we are all in agreement on our love of airguns (and they are extremely cool! =>), we may hold varying opinions on a variety of other topics, yet we treat each other with caring and respect, which I think is fantastic.
    (And if anyone ever thinks me guilty of not doing so, please call me out on it.)

    I love this blog; I actually pray for it; I pray for B.B., for this blog, and for everyone who reads it.
    Yes, some may find that silly; but if you are reading this, someone prayed for you today, for your well-being…and that would be me, since, from my point-of-view, all of us reading this blog do so only by the grace of God.

    Hence, I pray for B.B. to live a good long life so we can all continue to glean wisdom from his reports, as well as from the data and comments we share.

    That being said, not every report “speaks” to me; and I don’t expect they all should. Years ago, a pastor friend told me someone complained that they didn’t always get something from all his sermons; he replied, “It’s not all meant for you; take what is, and leave the rest to whom God intends it.”

    Some reports get me fired up and excited; others may not “speak” to me directly, but then I’ll see by the comments that others (the ones for whom they are intended) are very passionate about the subject.

    And I love that, years from now, other airgunners will be reading through these reports and commentaries and (hopefully =>) gleaning wisdom from them. I think that’s awesome, and it makes me proud to be part of this community.

    If I offend anyone here, please know that’s never my intent; I love all y’all (note the correct use of Georgia terminology =>), and I really enjoy this unique community.

    Peace.
    Blessings to all,
    dave

    P.S. B.B., to you especially I say, “Take care,” like don’t accidentally step out in front of a bus or something; we need you; and we’d like to see you continue with this blog for years to come.

  2. B.B.,

    With each barrel inch increase on most Big Bores beyond about 24 or so inches the gain in energy/velocity starts to fall with fixed input values at an ever increasing rate in my experience.
    The enjoyment of shooting a rifle Off Hand seems, in my opinion at least, to increase with every inch shorter until the same 24 or so inches is reached.
    Having never shot a Big Bore Bullpup I don’t know if that configuration makes up for it at some other barrel average length.
    In full auto medium and large caliber firearms not having my non trigger arm out front, with or without a sling, made me spray larger patterns which might have been simply less experience controling the recoil and muzzle wandering. I didn’t like it.

    shootski

    • Fish,

      Yea! Fortunately many manufacturers are building Air rifles using mostly to specification 1913 PICATINNY rails so that can be done with aftermarket parts.
      I actually had the Weaver Mounts on my DAQ Outlaw .58 Caliber Pistol replaced with a 20 MOA RAIL so I could use flip up Magpul BUIS and a tube Red Dot.

      Shootski

      • Well, on those rails, you can use any sights, including aftermarket ones; some Hatsan PCPs have those rails and some don’t. What I want to point out is the fact that Hatsan actually produces amazing sights without fiberoptics. I want to see sights without fiberoptics on Hatsan springers too — not only as pieces for those rails.

  3. The first thing that entered my mind when I picked up the FX Indy Bullpup was, I wish they put this one out first. And I much prefer the Hatsan Gladius Long over the AT-44. Mostly because they are much easier to manhandle and shoot from a standing position. They feel well balanced and comfortable to me.
    You lose all that “A body in motion tends to stay in motion.” feeling when you swing them around.

  4. B.B.,

    You mention blackpowder, but I think it would be more accurate that you are describing muzzleloading guns, and I imagine that there would be a similar danger with the vent hole of a flintlock as there was with the nipple of the percussion gun.

    As far as I can tell, blackpowder metallic cartridges shouldn’t pose any issues particularly different from modern cartridges, aside from the rate of fouling.

    Cheers,
    Nathan

      • BB

        I have always been perplexed that my cap and ball black powder pistols didn’t blow out the nozzles on every shot. Your story happened just before I discovered your blog. While the much heavier projectile changes the reloading guidelines I still wonder. The first time I actually shot a black powder wheel gun I stood so that a tree was between my head and the pistol.

        Deck

      • That was a close call with your black powder-burner, but glad it was not worse. Probably wise to retire the Nelson but for some strange reason this story has given FM an itch to cancel the .58 cal.’s long vacation and shoot it a few more times. Gotta get more “minnys” – sorry, FM likes quotation marks so he will keep them, he will keep them – and a little powder. Sticking with the original propellant recipe, says somewhat purist FM.

  5. BB,

    I would not want anyone to get the wrong idea about me. You left my quotation marks off of “real” weapons.

    I guess I watched too much Daniel Boone and Davy Crocket growing up. I like the Kentucky long rifle.

    P.S. As for squirrels charging out of concealment and goring someone, there are some nuts out there who should stay away from the woods.

  6. My only bullpup is my Huben K1. It is an amazing gun due to all its advanced tech (hammerless valve, flawless semi auto capability etc.), and the nature and package of that tech kind of makes it almost better suited to being a bullpup than a conventional rifle. The trigger on it is excellent, although it is not equal to my Air Ranger or tuned Marauders with Rowan Engineering trigger blades. It has a little slop on initial take up, but has a good first stage with a solid wall for the second stage, and a very clean and light break. It also has minimal travel to reset for the next shot – just the second stage needs to reset, so I can easily shoot all 19 shots in under about 5 seconds if I don’t care that much about precision 😉

    What I clearly see with the format is that while it shoots great offhand – it just feels and points so right – it is greatly lacking when shooting for accuracy when rested. They are clearly top heavy, and the best word that comes to mind is “twitchy” in behavior.

    When shooting for accuracy from a front rest and rear bag, the Air Ranger is just effortless – it is so easy to get dead on target, and I can hold it there indefinitely. And when I let the shot go, it always fires dead on where I intended, and any slight variation is from the gun/pellet (with it’s best ammo at 21 yards indoors at least 8 of 10 shots will be in the same hole, with maybe up to 2 being a mm or two off that ctc). My Marauders are similar, if not quite as accurate.

    The Huben is impossible for me to shoot as well in the same situation. The sight picture seems to be always moving, and I simply can’t pull off ten shots in a row in that situation without a called flyer in which I did not release the shot dead on where I wanted to – and that is despite the fact that Huben has probably one of the fastest lock times of any air gun out there (due to the hammerless valve).

    If the Huben was as good as the others from the bench, I’d probably sell everything else and just own the K1 (or maybe two of them). But it is clear to me that bullpups are probably best for what I will call dynamic shooting situations, and probably can’t compete with conventional rifles from a rest – that “twitchyness” clearly has nothing to do with the Huben specifically, and is a function of its form factor.

    I will add that the Huben itself is quite accurate, but is not equal to the Air Ranger – I expect in part because it shoots from the magazine, leading to more variability in each shot. But it is more than accurate enough for any “dynamic shooting” situation, if not for benchrest.

  7. BB,
    I only have two PCPs, a synthetic gen 2 Marauder, and a Kral Puncher Breaker Marine Silent (a bullpup with quite a name). Both in 22. I bought the Marauder several years ago to both hunt and plink with. But I hunt most of the time with my nephew, who has cerebral palsy, in a pop up blind. We are actually deer hunting, but we are also watching for squirrels or whatever else comes along, and the Marauder being as quiet as it is, excels at that. However, with the two of us in there, a gun as big as the Marauder is really unhandy. The Marauder is bigger than my deer rifle. Thus the desire for the bullpup.

    That’s my story on why I wanted a bullpup. Your mileage may (probably will) vary.
    CB

  8. For the brief moment before my eye/brain caught up and found the barrel, the opening image had me wondering which way the bullpup was pointed 😛

    And perhaps due to the recent Fat Tuesday, it also looks a bit like a party mask!

    I’ve not seen one in person yet. Who knows, I may find I really like them if I ever get to shoot one some!

  9. B.B.
    That story about your gun blowing up was scary to even read. I too had a gun blow on me. I was shooting my trusty H&R 12 Ga. single shot shot gun. I was shooting paper hull shells (Just birdshot normal loads, nothing hot). I pulled the trigger and boom, I couldn’t see or make out what was happening it happened so fast. I felt stuff hitting my face along with the concussion of sound hitting me. Even though I had ear plugs in, the sound was so loud my ears were ringing. I put my hands on my face expecting it to be half blown off. No blood or nothing. I looked at the gun and the breech had broke open. The lock had failed. What hit my face was just bits of the paper hull of the shell. I don’t know what stopped the brass head from hitting me (for all I know it did). I was young and had no glasses on. I was able to live and learn.
    All that said, myself, not owning a PCP, have always been shy about having something near my head with 3000 psi in it. I don’t know what psi a scuba or wielders gas tank has in them, but they have safety caps, I’ve watched videos of them blowing off when dropped. Could them happen to the nipple of a PCP if dropped? Just wondering.

    Doc

    • Doc Holiday,

      Depends on the builder of the PCP.
      Dennis Quackenbush’s site has a great discussion on pressure vessel safety and about Steel in general: http://quackenbushairguns.com/steel_for_airguns.htm
      He writes in a way that doesn’t make it too difficult and he knows his business completely.
      These days SCUBA (Self Contained Underwater Breathing Apparatus) 3,000 to 4,500 psi, SCBA (Self Contained Breathing Apparatus) and Carbon Fiber (CF) Cylinders are typically filled to 4,500 psi.
      The really big/tall steel commercial gas cylinders are 6,000 psi and up. There are CF cylinders that hold 20,000+ psi…not air but specific gasses.

      shootski

  10. For the most part, I don’t go back to old blogs unless I receive an email notice about a reply to a comment or have a special interest in the subject. That’s why I revisited the last Dragonfly blog and may continue to do more of it now.
    What a surprise to see all the comments that resulted from my facetious statement about Global ‘Warming’ causing extremely ‘Cold’ weather here in San Diego and then the continuation into religion. Truely an outstanding blog here for comradery as well. And then there were even more entries about … Oh yes, the airgun. Appreciated the picture with the scope on 🙂 Thanks Tom for letting the Blog take on a life of its own.

    I have lived in California since 1971, two years in Alameda and the rest in San Diego, 50 years. I do see a change in the weather here. Sometimes it feels like there is no spring or fall and then there is the drought. I worked outdoors, for the most part, all that time. The summers are hotter and winters colder.
    From what I’ve found out it’s like a thousand-year cycle and why the west was not overly populated early on. I think we are influencing the climate some but not the daily weather too much. The wind stream seems to be the big player here. Way too complicated.

    About religion. I was raised and educated Catholic but couldn’t take it any more after my first two years of HS, too academic for me. I transferred to a public HS where all my friends were. No more suit and tie.
    The best I can say is that they educated me enough to figure out that the Catholic Church is more like a business than a religion. Especially after the way they milked my mother, and their parishioners, out of money in her old age. Never touched a Bible in 10 years with them.
    It’s just me, God, and the Golden Rule now.

    I believe we may have exhausted current technology in airgun development but have a lot of fine tuning of the sport left ahead of us. Like pellets for example. Can’t imagine what’s next.

  11. BB.
    Scary situation with your black-powder blow up. But it is not always gun age and proof charges that bring consequences, most often is the human factor. I remember a range I used to visit had in prominent display a nice partially de-constructed rifle – product of what Elon Musk would call a RUD for ‘rapid unscheduled disassembly. The user inserted a cartridge with .308 bullet in a .270 barrel. The strong bolt action, I was told, limited the injuries to minor levels.

    On the subject of bullpups they are indeed in favor of several military forces – UK’s L85A1 and the French FAMAS come to mind – and they are represented in several PCP air rifles. What I have not seen is a spring piston air rifle in this configuration. Has anyone attempted to make one of these?

    Best,
    Henry

    • Henry,

      This doesn’t count because they are pistols, but the Hy Score 700 and 800 both have the mainspring in the middle of where the trigger sits.

      BB

    • Here you go Henry. Found this on YouTube. It can be done. A side cocking springer.
      Also look up the Industry Brand QB57 Bullpup airgun.
      There was the Norica Goliath 88 Classic Carbine, but I think it was a pistol with a longer barrel and a stock added.

  12. A little off and on the conversation.
    Why do we do stupid things with guns or anything in general? … Just what is STUPID?
    It is generally defined as having or showing a great lack of intelligence or common sense.
    Those are symptoms.
    The scientific concept is a failure of our brain to use one’s cognitive abilities effectively. A failure to be aware of our limitations and abilities. It affects us all to some degree.
    It’s called the Dunning-Kruger Effect. Just read this and it’s very interesting. We can be ignorant of our own ignorance.
    And I was wrong a while back stating that college did not make you smart but educated. Seems it does reinforce the brains’ cognitive ability but I doubt if it fixes any genetic problems.

    • Bob M,

      “Why do we do stupid things with guns or anything in general? … Just what is STUPID?”
      I think you have what STUPID IS down pat.
      But why we do stupid things?
      I believe it is not always out of direct ignorance but simply caving to Pear Pressure or the need for many humans to conform. Conforming behavior afterall is trained in schools from the moment you walk into Kindergarten or maybe Pre School which results in some believing it will result in acceptance by others.

      I combine shooting and skiing…does that tell you something about me? Is that STUPID? Non-conforming…yup probably.

      shootski

      • Shootski
        If it’s not beyond your capability, it’s not stupid at all. Risky perhaps and the reward may override it. It tells me you are a thrill seeker. 🙂
        Doing it without practice would be stupid. But I get your point. Why do we actually do something we already know is stupid? And I believe you are correct.
        Overriding your brains common sense when you know it’s stupid is Moronic. Kind of like smoking when we are now aware of all the health problems associated with it. But that involves addiction so it may not be a good example.

    • What gets me is stupid usually doesn’t feel right. But what is more stupid is why do we continue at that time to do that stupid thing till it happens.

      Did the brakes go out? As in no stopping!!!
      Here comes stupid… Why did stupid continue?

    • Fish, on February 8, 2013, Tom Gaylord, a.k.a. B.B. Pelletier, wrote in the article “Nelson Lewis combination gun: Part 4”, that the exact condition of the nipple, prior to the accident, was not known, that the nipple could not be found afterwards and that now, the left barrel has a new nipple, screwed into a replacement heli-coil thread.

      I was fascinated to read about the skilful repair, including multiple illustrations, by his late, highly skilful mechanic friend, Otho ! 🙂

      Also, I wonder if you too think it amazing, when you see what Otho did to a Colt Single Action Army of his dad’s? 🙂

      There is even a picture of Tom Gaylord ‘playing’ a one-stringed instrument… 🙂

      https://www.pyramydair.com/blog/2013/02/nelson-lewis-combination-gun-part-4/

      • hihihi,

        I was not able to read this installment until this morning, but I had to say that your Bullpup is too close to Bullp__p made me crack up. Out loud. Thanks for that.

        Michael

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