Parallel-Bore Side by Side Shotgun – Look Ma, No Rib!

Virtually all side by side shotguns are not actually made with the barrels parallel – they are made pointing just slightly together, so that the shot patterns will converge and meet up at a particular range. Today, we have an Ellis Brothers (of Birmingham) sporting shotgun that was actually made with bores that are entirely parallel – and it looks quite unusual when one is used to the traditional configuration!


  1. I don’t know how the barrels are meant to be used. Skeet shots are unlikely and birds even less likely to get hit… unless you target annoying drones.

  2. Simply joining the optical axis of bores at a given distance can not provide correct barrel regulation. lt can be accomplished through supported actual shooting and even if it could be made correctly, it would be true only for a certain mass and speed of loading, mass of gun and shooter, phyisical features of gun holding and pitch and twist of stock. Only user’s kind of variations might be minimized through special order guns, other parameters would go on. Parallel axis barrels might be true for special sidewardly angled stock shotgun.

  3. That looks like a staff officer’s badge in the stock (the crowned lion on crown), the original owner was probably a big shot army man. There were initials too, so it might be possible to identify him.

  4. I was wondering if it was a paradox gun (rifled the last few inches so you can use shot or bullets) but I didn’t see any rifling, and with the birds as decoration…probably not.

    But that engraving! Even on the inside of the forearm!

  5. Beautifully decorated gun. I never owned side by side so I did not pay much attention to barrels alignment. If barrels are parallel as it seem to be here, it probably does not make much difference where pellets go. Dispersion will make up for it; my guess.

    One thing which I like about shotguns in particular is their thin barrels at muzzle; it looks very elegant. Recently I looked at one page with recommended thicknesses for various calibers including shotguns. It was, if I recollect it right, at muzzle for 12 gauge 1.5mm. Impressively thin.

    • “It was, if I recollect it right, at muzzle for 12 gauge 1.5mm. Impressively thin.”
      Well, 12 gauge is in fact low pressure even compared to rifle cartridge originating from 19th century.
      SAAMI maximum pressure (so pressure measured near muzzle will be not greater than) are
      12 gauge (3.5 inch) – 14000
      12 gauge (all others) – 11500
      for comparison:
      30-30 Winchester – 42000
      ·303 British – 49000
      45-70 Government – 28000

  6. I did some guessing about the Convergence of Shoot Gun Barrels:
    Eyeballing the distances of the double barrels middle to middle
    I would say its about 31mm at the breech and about 21mm at the muzzle.
    Assumed the barrel is 71cm long and the barrels are not bent somehow,
    I came to the conclusion that both bore axis are crossing at a distance of 1.55m from the muzzle end. At a distance of 50 Meters the axis came appart 0.66m again.
    Somewath questionable results I would say.
    Could this be true or did I miss something ?

    • Hitting place would not be the seen point or location through the barrel axis… When fired; According to the weight of user, gun and loading and tightness of hold and touching place of stock in relation with fired bore axis and the centre of the gravity of whole rational masses, the gun slightly would rotate and the projectile would go as deviated where the barrel axis points.

  7. If Ian gave the date of this shotgun I missed it. Also how were the barrels made? Looks like a type of damascus but it’s much more regular than other damascus barrels I’ve seen.

  8. The barrels of shotguns (and double rifles) are arranged with converging muzzles in order to anticipate the displacement that occurs in the recoil phase before the load departs the muzzle. Because the right-hand barrel of a side-by-side gun is arranged to the right of the stock centerline (and the left-hand barrel to the left) recoil will cause a right hand torque about the butt end of the stock and the barrel will swing to the right. Building the barrels with converging center-lines results in them being (approximately) parallel at the moment the load is discharged.
    A similar phenomenon occurs with over-and-under designs, except that the center-lines of the barrels are different distances above the point of rotation at the butt end of the stock; causing the top barrel to ‘shoot’ higher than the bottom barrel. The solution is to build the top barrel with more ‘downward alignment’, which is achieved by building the barrels with converging barrel center-lines.
    Matters are complicated when substantial cast (offset) is added to the stock of a side-by-side gun. 1/2 – 3/4” of cast will set the center-line of the butt end of the stock close to, or precisely behind the center-line of one of the barrels. For a right-handed shooter using a cast-off stock the right hand barrel will have less sideways moment in recoil then the left. This may account for why some side-by-side shooters are more confident when discharging the right-hand barrel, than the left.

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