.410 Bore

Early Development

The true origin of the .410 shot shell cartridge is nothing if not unclear. By the end of the 1870’s both centrefire and pinfire shells of .410 bore size were known in Europe. A very similar (if not identical) chambering, known as the “12mm” in Germany – possibly a reference to the outer size of the cartridge at the case mouth of approximately 12 mm – was also known. When expressed in Imperial units, the bore diameter of the 12mm cartridge was approximately 0.410″ and certainly, by 1878, the terms were being used interchangeably in adverts for guns and ammunition designed for use with smooth bore guns of that size. It was not until well into the twentieth century that the standardized dimensions for the cartridge were fixed.

By the end of the 1880s, British gun makers were submitting .410’s to the London Proof House on a regular basis. Likewise, “12mm” shotguns were being submitted to European proof houses and the (as yet unresolved) controversy as to effectiveness of the .410 / 12mm for shooting game had begun in earnest in the shooting media of the time. There may be a reason for this: early cartridges for the .410 were invariably of 2″ in length and formed from hammered or drawn brass. They almost always contained 3/8oz (approximately 10.5g) of shot atop a charge of black powder. The only examples of cartridges and cartridge boxes for this early period which the author has been able to find display shot sizes no smaller than #6 with many examples of #5. This suggests a pellet count as low as 80 – hardly a pattern to speak of!

By 1900, general improvements in cartridge design made practical the production of paper cartridges for the .410. Although various kinds of brass-cased loadings remained commercially available for some time afterwards, the major manufacturers – Eley, Kynoch – moved to eliminate pinfire cases and brass centrefire cases from production by the end of the second decade of the twentieth century.

During this brass-to-paper transition period Eley and Kynoch both independently developed the 2½” cartridge for the .410, a development no doubt assisted by the ease of forming cartridges of greater length from paper compared with brass. Surely intended to address the limitations of the 2″ case, the new cartridge was typically loaded with 7/16oz (approx. 12.5g) of shot and by 1914, Eley had begun to market the well-known “Fourten” and “Fourlong” brands, which continue in production to this day.

Over The Pond

On the other side of the Atlantic, the .410 was starting to find employment amongst American pot hunters who appreciated the lightness and “pointability” of guns bored in this size.

A myth seems to have grown up that the .410 shot shell was derived from the 44-40 Winchester cartridge, via the .44XL shot “shell” which certainly seems plausible since both (all three) cartridges have very simillar head diameter, rim diameter and rim thickness. However, it appears from reliable sources that although the dimensions and early utility of both of the shot shell -type cartridges were used for similar applications, they were independent developments.

The .410 had probably arrived in earnest by about 1900; certainly by the 1910’s the major American manufacturers were producing .410 ammunition on a large scale and by the middle of the decade, (2″) shells aimed specifically at repeating shotguns, beloved of our cousins, were in mass production, containing every shot size from #1 to #12!

In 1915, Remington tried a new, radical approach to solving the problem of pattern insufficiency in the .410 and reduced the length of the case to 1½”! The author has no information pertaining to the reasons for this “development” or with what this short-lived cartridge was loaded, but supposes that the intended use could have been shot pistols or revolvers where the size of action required for a 2″ cartridge would have rendered a hand gun somewhat unwieldy. However, short of loading the shells with lead dust and using them to kill bluebottles and house spiders at ranges of up to and including six inches, it is not clear what ballistic advantage may have been sought.

It took a few more years for the 2½” .410 shell to be fully adopted in the USA, but by 1920, a similarly large array of loadings were offered by Winchester for 2½” .410 as 2″, with the other manufacturers not far behind.

Pattern Insufficiency & The 3″ Case

Although Pietro Fiocchi had probably correctly identified the .410 as having the smallest suitable bore size for a “serious” hunting shotgun, it is undeniable that otherwise competent shooters were restricted to shooting quarry at much shorter ranges than they were otherwise capable, simply because it was not possible to pack enough pellets into the available cases to reliably and cleanly take – for example – English game birds.

There is an argument, of course, that this was never the intention behind the .410’s development. In warmer climes, where farming was (and remains) more oriented towards fruit production than cereal crops, the .410 had found a niche – which it continues, to some extent, to occupy – as a crop protection tool against the migratory birds which ravage olive groves, wineries and orchards. These are such small quarry that shot sizes of #9 and smaller are quite suitable for their control and the small capacity of even the 2″ case is therefore no handicap to gaining an acceptably dense pattern. Of course, ranges of shooting remain necessarily short.

Remember too, that the .410 was first developed in the era of black powder and wool wads, which themselves took a lot more case volume than modern components and gave inferior performance compared to smokeless powder. Muzzle velocities of 900fps – low enough to keep the chamber pressure from overwhelming the gun – were not slow for the time, but this did not seem to worry our forebears: there was perhaps not the same expectation that every shotgun should give 50 (or even 40) yards of usable range that there is now. It is clear, however, that the maximum range of a .410 used against medium game birds may have been 20 yards or shorter.

As is the usual human way, however, shooters remained unsatisfied with their lot and demanded greater performance from the .410, seeking a (more) useful small-to-medium game gun. With pattern insufficiency the main complaint, the Ithaca gun company in America experimented with new shell lengths of 2 3/8″ and 2 7/8″, which were not uncommon in the larger gauges in the first half of the twentieth century. Neither caught on.

In 1927, the Midland Gun Company of England created a double gun with 3″ chambers whilst the newly-formed ICI supplied ammunition for it – the “magnum” .410 was born. The shot charge for the new cartridge was initially set at ¾-oz (21g) of shot. Although apparently initially popular, the ¾-oz loading would have had a very low muzzle velocity and likely patterned appallingly. The “standard” shot charge was quickly reduced to 11/16-oz, which is in the region of 19½g, although lighter loads with shot charges as low as 9/16-oz (c. 16g) have usually been available since.

Once again, it took a few years for English developments to be emulated in North America and Europe. In 1933, Winchester finally answered the calls of American hunters with the introduction of a 3″-chambered Model 42 and manufactured cartridges for it in-house. Other American manufacturers soon followed suit.

Slug Loads & Final Refinements

It took until the late 1930’s for commercially-loaded slug ammunition to be made available for the .410. A 1/5oz. slug was set as standard, with Winchester producing a rifled-type just before the outbreak of the Second World War in 1939. It has generally been considered adequate to take medium ground game, perhaps up to the size of a large fox, at ranges up to around 50 yards, but many reports suggest that even in the best-tuned combinations, accuracy tends to be appalling.

In 1961, the “Permanent International Commission for the Proof of Small Arms” (generally known as “C.I.P.”) finally settled on a designation and standardized measurements for the .410, reversing its earlier decision to use the inaccurate description of “36 gauge” (it would actually be a 67½ gauge).

It was not to last. The dithering by the Commission, for over 70 years, as to what the official name for the gauge should be had lead to the long-term adoption of the terms “36 gauge” for the 2″ & 2½” shells and “36 gauge magnum” for 3″ shells in mainland Europe and these were too well established in the minds of users to be changed arbitrarily. In 1969, the name “36 gauge” was appended to the official name in parentheses and thus it has remained.

Whilst the bureaucrats dithered, the arms manufacturers prospered and hunters hunted: by the end of the 60’s, plastic shells, roll crimps and then fold crimps all began to make an appearance in shotgun ammunition and these developments were applied to the .410 equally. Since then, better formulations of powder (and powder geometry) and more sophisticated wad design have made for some improvement in what can be expected from the .410, but guns and ammunition still suffer from the inherent limitations of such a small tube.

The 21st Century .410

Today, the .410 appears to have gone full-circle. Having been adopted, early on, as a suitable cartridge for a gentleman to employ for self-defense in the walking stick guns which were common at the turn of the twentieth century, the American “home defense” market has rediscovered the cartridge and its popularity for this purpose has once again risen. 3-ball and 5-ball buckshot loads have recently appeared, as have (absurdly large) Taurus pistols chambered for the 2½ and 3″(!) cartridges. (We think that the advantage of a spread effect pistol in a self-defense situation is likely to be outweighed in some cases by  a complete inability to pick the gun up! – Ed.)

For hunting, the .410’s use as a gun for wingshooting has always been somewhat niche and remains so. At SmallBoreShooting.com, we suspect that much of the recent emergence of better information, loading data and the “.410 driven day” has been as a result of the internet and a small band of enthusiasts who have the patience and inclination to match gun and cartridge so as to extract the best possible performance out of the bore size. Of course, it is easier just to use a 12 gauge and we’re not looking to argue with that fact – but we do look to speak for and support those who want to try something different.

Outside of wingshooting (and of course, it’s practice form, skeet), the old favorites of rabbit / rodent control and the dispatch of quarry caught in traps remain the .410’s most common uses. A few folk in the UK – perhaps a greater number abroad – have access to .410 slug ammunition and use them for varmint shooting but these shells do not meet the requirements of the Deer Act 1991 and Firearm certificates are not granted for this purpose.

Outside of the UK, fewer restrictions exist and slug ammunition is more widely available, but their effectiveness on game larger than fox remains marginal and their accuracy compared to a more suitable rifle ought to prevent the .410 loaded with slugs from being anything but a gun of last resort.

In spite of their limited utility to most, .410’s remain a popular “second” gun, after the ubiquitous 12 gauge. Although the 28 gauge is a far more useful and capable gauge for teaching young and slightly-built people to shoot, many folk still report that their first experience of firing a shotgun involved the use of a .410. In many cases too, the experience leaves a lasting impression – 20 years after firing a .410 for the first time, the author finally managed to acquire a double gun of the sort he first used and now wanders the hedgerows with it, learning to hunt with it, prompted almost entirely by that one, enjoyable memory! (See elsewhere for an account of that education.)

In the end, then, the .410 will go on, its place in the pantheon of cartridges and arms now firmly established and those of us responsible for this website will go on using them. We hope that those readers who have them will continue to do so too and that those of you who don’t might be persuaded of their usefulness by this article (and the others presented here) and acquire one.

Happy hunting!