Rifle design question: Bullpup vs. std. shape?

Factual Questions
1

Im just curious as to why you would choose one design over another.
I mean, what advantages and disadvantages are there in the bullpup vs. standard rifle shapes?

2

AFAIK, it’s mainly the position of the receiver vis-a-vis the pistol grip/trigger group that’s different in a bullpup rifle.

You can have a standard action in a bullpup configuration- see the Valmet M82. It’s a regular old Kalashnikov action in a bullpup configuration.

The main advantage is that the overall length of the weapon is shortened without giving up any barrel length or sight radius, since the whole receiver/magazine well is back behind the pistol grip and is where most of the stock used to be.

3

Once I determined that a particular rifle is accurate, I would consider the weight of the rifle, then the weight of the ammunition. At this moment, the AR-15/M-16 is the best rifle in the world, because it is the lightest rifle design in spite of the Bull-Pup designs. Its days are numbered to be sure, there will be better rifles designed in the future, but right now it is the best there is.

4
      • Standard rifles evolved from early matchlock and flintlock rifles that had ignition systems that did not permit bullpup designs–the breech of the barrel had to be well forward of the shooter’s face, because muzzle blast would come out of the ignition hole used.
  • Bullpup rifles are shorter and faster to draw overall, but they can be more difficult for left-handers to use (if they eject to the right side). Another common difference cited is that they are not as easy to reload under pressure as a regular rifle is, because the magazine well is harder to see on a bullpup.
  • Standard rifles do continue to have an advantage in that the parts placed under the most stress are located a few inches away from the shooter’s body. If the breech of a bulpup rifle explodes, the shooter’s arm and chest are going to get hit with lots of debris. There have been incidents of modern rifles exploding at the breech and the shooter suffering little or no injury (at least one Springfield Garand, and I think an M1A went somewhere also but I cannot turn up any links at the moment, the ones I am finding are all dead. Gimme a couple hours on this…).
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5

Interesting article on the shambolic history of the SA-80 (aka L85 Individual Weapon), the UK’s bullpup rifle.

6

Both these are military-type arms, and the injuries sustained were minor. I haven’t gotten any links to examples, but people on gun boards have noted that when ordinary hunting rifles explode, often there is serious injury to the shooter.
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7

Another issue with bullpups is parallax though it’s not considered much of a problem with military weapons. With a conventional rifle the comb of the stock - the part your cheek rests against - can be dropped relative to the barrel centerline. This allows the line of sight to be very close to the barrel which can be helpful for high precision. With a bullpup the sights have to be raised a few inches above the barrel.

An advantage of that same issue is that the centerline of the barrel is usually in direct line with the top of the buttstock rather than above it. This keeps all the force vectors a little bit more in line so there can be less muzzle rise when firing.

Incidentally because of the buffer design of the M-16 which goes through the buttstock both those factors are true even though it isn’t a bullpup.

DougC, there is a modern bullpup muzzle loader. It uses inline ignition so the shooter is shielded from blast from the percussion cap. I don’t think anyone has been fool enough to try and build a flintlock version.

8

Bullpups can be a bit harder to use ergonomically as far as changing magazines and such. Another thing to consider: Soldiers don’t wear ear plugs in combat, and having the muzzle closer to your ears is unpleasant to say the least.

Overall, though it allows either a shorter weapon, or a weapon of the same length to have a longer barrel.

9

So why choose one over the other?
Ive noticed that a lot of modern designs are bullpups, particularly in submachineguns.

10
      • What submachine guns are bullpups? To be a bullpup the magazine has to be inserted behind the trigger grip. There’s still a few submachine guns that have a pistol-style well in the main trigger grip, but most use a magazine well placed forward of it The only few bullpups I can think of right off are the British one mentioned, the Swedish Valmet, Olympic Arms or some other civilian-M16 company in the US made a bullpup rifle based on the M16 internals at one point, and there’s a bullpup version of the AK-family from somewhere in eastern Europe…? And if I am remembering right, there was a South African-made one at one point, I never read much about it… -And then there’s a kit out there to convert a Ruger 10/22 into a bullpup, I guess if we’re counting all of them… That’s only five possible current bullpup rifles produced wirldwide (six if you want to count the 10/22 kit) compared to dozens of currently-produced conventional rifles…
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11

I always wore earplugs in a fight. But that was just me.

12

Bullpups: SA-80 and variants (the L85 Individual Weapon, L86 Light Support Weapon [LMG] and a training rifle), the FA MAS (French Army), Steyr AUG, Enfield EM-2 (predecessor of the SA-80), Valmet M82, Type 86 (PR China AK-47 clone with bullpup design), US Bushmaster M-17S and the AKU-94 conversion kit.

13

Israel Military Industries (IMI) has also developed a 5.56mm bullpup, the TAR-21 Tavor (Here is another overview). The IDF has been considering it - and testing it - for some time now. The general asesment is that besides the fact that it is slightly heavier, it’s superior to its alternative, the Colt M-4, in accuracy, reliability and ergonomics. However, it’s not an easy choice: while the Tavor is pretty much agreed to be the better weapon, and they believe Israel (which sees itself the military equal of the UK, France or Germany) should sport its own indeginous assault rifle, the M-4, which is supplied by vthe U.S. as part of its military support, is much cheaper, more familiar and much more battle-tested. I suppose they’re also slightly leery of the whole bullpup concept.

The latest news is that the IDF decided to purchase 15,000 Tavors to equipt its Assault Infantry Brigades. However, I haven’t seen any evidence of this myself.

14

I don’t recall ever seeeing a bullpup SMG with the possible exception of H&K’s weird mini planet of the apes style PWD. There’s not really a need for a bullpup SMG as they don’t have long barrels to begin with.

I think this is a good example of something that looks terrific on paper but doesn’t feel as good when the rubber meets the road or in this case when cheek meets stock.

15

So far ignored in our discussion are the well known FN P90 submachine gun as seen in The world is not enough ( i think?) and the less well known FN2000 rifle system.

the P90 solves the ejected round problem by ejecting spent casings straight down, so the only problem would be burning one’s legs with hot brass if wearing shorts.

The FN2000 rifle actually has some kind of mechanism where the spent brass is ejected FORWARD of the rifle, via a port beside the barrel ( i think, the details seem rather sketchy to me).

Without any knowledge as to how this mechanism works, I’d be willing to bet that it would be horribly complex and probably not suitable for military use.

And let’s not forget the famous HK G11, which was technically a bullpup rifle too.

http://www.ets-news.com/herstal.htm

Another point against the military use of bullpup rifles: the designe does not lend itself well to the adaptation of large capacity drums or magazines, so it would preclude any LMG variant of the weapon ( how would you put a 200 round drum on an SA-80?)

This doesn’t seem to have stopped the chinese with their LMG variant of the new QBZ95 bulpup rifle, but untill i see a picture of someone actually shooting such a weapon it is a mystery to me what kind of fireing position you would get into in order to fire the damn thing…

16

The Russians make a 9x18 (or is it 9x19?) submachine gun based on the Kalashnikov action which is called, I think, the bizon.

17

augh. Sorry. They arent sub machine guns. (I appologize. Im still learning terminology of weapons, and I keep calling what are technically Rifles either Machineguns or submachineguns. My brain has hardwired “rifle” to mean something else, so…)
I of course meant rifles.

I’ve been reading different things and Im still curious as to why you would want to choose a bullpup design over a conventional one.
I (that is to say someone who knows little on the subject) would think that the bullpup would allow greater control in shooting, but one article Ive read mentions that it forces the soldier to be more exposed when firing. So again, why would you want to use one design over another based solely on design and practicality and disregarding tradition or what people are used to or cost of manufacturing, etc.

18

The term you’re probably looking for is “assault rifle”… submachine guns fire pistol ammo.

Anyway, as stated, the biggest advantage is the size of the weapon. Some designers think it’s a good tradeoff, others don’t.

19

Bullpup designs might be a viable option for paratroops or tank crew members. Come to think of it, anywhere that the old M1 carbine had applications might be a good place to field a bullpup design.

Having said that, I am no big fan of the bullpup design. They may make some sense in the area of ergonomics, but they are such a dramatic departure from traditional design that many troops are not happy with them. I can actually see some advantage to having the magazine well closer to the body and having a short over-all length (think one-handed operation).

BTW, I am surprised no one has yet mentioned the Mossberg bullpup design shotgun. What a beast to shoot. And does anyone remember the old High Standard M10 variants? A fun gun and great for breaking contact. http://world.guns.ru/shotgun/SH26-E.HTM

20
      • I also note that bullpups are not seen as good choices even for crews that work in close-quarters vehicles (such as tanks and other armored vehicles) because the whole point of a bullpup is to allow using a full-powered rifle caliber in a more compact arm. The practical problem with using full-powered calibers inside a small, bullet-proof vehicle is that flak from the bullets can easily bounce around inside the vehicle, harming the shooter, and another problem is that the noise levels from full-power rifles are extreme. Tank crews generally want to carry compact pistol-caliber guns for the purpose of their own protection, either submachineguns (in pistol calibers) or just pistols–and have since at least WW I.
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  • Bullpup military rifles seem like a good idea (making the gun more compact to carry and use) but in practice aren’t. If the magazine feeds from the bottom, the shells have to eject from the right side (because the top and left side are blocked by a right-handed shooter’s head and left arm), and so then 10% of soldiers (lefties) can’t shoot it instinctively. The drawbacks end up outweighing the advantages.
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