Barrel length

[hayboy]

I'm enjoying the thread.
Nothing definitive yet though.
I'd agree that you would THINK there had been some calculating and testing done to come up with the SMLE barrel length.
I will throw in rate of twist, but that gives a rotation of 2.52 by the time the bullet exits the barrel - doesn't leap out at you as of any significance...

Jon

[Alan de Enfield]

Makes sense for the later No, we know what we have, let's not fix what isn't broken. Still leaves the question of why that barrel length with the SMLE. Arbitrary half way between Long Lee and Carbine as Englishman proposes?

While on this topic, the P14 had a slightly longer barrel... ?

It is many years ago since I read the selection criteria but I'm pretty sure it was the only compromise acceptable to both the infantry and the cavalry. The infantry refused t have it 'even an inch longer' as it would not be 'manageable' when mounted.
The Infantry conducted tests with various barrel lengths and said the loss of accuracy, if they went any shorter, was not acceptable.

I'll have to rack my brains to try and remember the document.

[Alan de Enfield]

There is a fairly lengthy explanation of the developments in the history of the 'Enfield' in Pegler's book

A bit around the introduction on the ShTLE


SAC seemed to have become almost obsessed with creating the perfect
rifle, and towards the latter half of 1901 it seemed that the solution may
finally have been found. Some 1,055 ‘Shortened Enfield Modified Rifles’
had been made at Enfield and sent for troop trials. The new rifle
incorporated a host of detail changes: these included a fully enclosing top
hand-guard along the barrel and two patterns of improved rearsight, ‘A’
and ‘B’, of which the former, graduated from 200 yd to 2,000yd (183–
1,829m), was eventually selected. Distinctive winged protectors were
fitted behind the rearsight bed and the straight-blade foresight was
similarly equipped with the addition of a novel and highly distinctive onepiece
steel forend, which both protected the sight and provided a secure
boss and lug fitment for the bayonet. Most significant of all, the rifle was
reduced in length by no less than 5in (127mm) and its weight by 1lb 4oz
(0.56kg), making it only 4.5in (114mm) longer than the Metford and
Enfield cavalry carbines.

The quality of manufacture and detail of these rifles was exquisite: ivory
knobs were fitted to the rearsight slide and fine adjustment provided for
elevation and windage. A modified pattern was sent for testing in mid-
December 1902, incorporating no fewer than 72 alterations from the Long
Lee-Enfield that preceded it. It was accepted for service later that month
(published in the List of Changes, 23 December 1902) as ‘The Short,
Magazine Lee-Enfield Rifle Mk I’. It is perhaps worth noting that over the
years, the comma after ‘Short’ has often been abandoned and many firearms
enthusiasts now believe that the nomenclature refers to a shortened
magazine, whereas it simply refers to the reduced barrel length of the new
rifle. Many units participated in the trials of 1902, including line regiments,
cavalry, Royal Navy and marine units. Although there were some minor
complaints, one persistent problem arose – that of poor accuracy on some
rifles – the reason for which could not immediately be determined.
Speeding up the loading process was also regarded as a major issue,
and after 1902 the first charger-loading Lee-Enfields were produced, with
five-round clips supplied for faster charging. To enable these to function
properly, the rifles were modified with the addition of a charger guide
attached to the left side of the receiver and the retrofitting of a new bolthead
with a sliding charger guide; as a result the distinctive steel bolt dust
cover was now omitted. Wear in the bolt-head charger guides resulted in
a steel charger bridge being fitted above the receiver, and this was to
become a permanent feature on all future Enfield models. A lever safety
catch was fitted to the rear left receiver.

These changes were just the beginning, though, for attempts to find
and correct the shortcomings with accuracy continued unabated.
Experimentation in 1904 at Enfield with different barrel types showed
that a short lead from the chamber into the barrel, allied to the adoption
of a new form of Metford/Enfield rifling, improved matters greatly. The
rifling modification required increasing the rifling twist towards the
muzzle, a configuration known as progressive rifling. It enhanced
performance by speeding up the rate of spin on the bullet and helping
stabilize it, but did not entirely solve the matter. Eventually a bore with
parallel but deeper rifling was introduced, but the two types co-existed
until almost the end of World War I.
Another immediate problem in introducing a shorter barrel had been
a slight drop in muzzle velocity to below 2,000ft/sec (610m/sec), and the
barrel modifications helped to raise the performance back to an acceptable
2,200ft/sec (671m/sec). (A full performance table for the .303in cartridge
is given on page 25.)
As a result of the testing, endless reports and recommendations, the
sealed patterns for the SMLE Mk I and Mk II rifles were approved on
26 September 1906 and began to be introduced for service on 26 January
the following year as the ‘Rifle, Short, M.L.E. No. 1 Mark III’. As was
inevitably the case, the number of amendments and design modifications
to the previous Mk I and Mk II were legion and space requirements make
it impractical to reproduce a full list, but the rifle that was to become the
most famous and recognizable long-arm in British military service had at
last taken on its final form.

[englishman_ca]

Ya, some coincidences with the barrels.

The cavalry carbine was a lightened arm for the horse soldier. The lightweight barrel was slender but fully protected by stock, hand guard and nose cap. Introduced 1894.

Introduced nine years later in 1903, the muzzle diameter on the Sht.LE is much the same as the slender carbine barrel. Take a carbine barrel and stretch it by 4-1/2 inches and you have an SMLE barrel. Coincidently also protected by a stock, hand guard and nose cap.

Then the black magic with the barrel harmonics to get the Sht.LE to shoot and compensate. Spring loaded inner center band, then a spring loaded centering shoe in the nose cap. The long Lee had none of that, just a heavy stiff barrel.

The heavy barrel created for competition use with the SMLE is basically a long Lee barrel shortened. Which coincidentally would be the same as the No.4 barrel. Eeek! Coincidentally, the barrel diameters and taper on the No.4 rifle is pretty much the same as that of a cut down long Lee.

What does all this mean? I have no idea. Just Enfield minutia.

But methinks that Enfield had some of the best engineers and designers of the time. The more I delve into what sometimes seems insignificant details, I recognise and appreciate some very clever work. The evolution of all things mechanical, materials and manufacturing processes of that time I find fascinating.

[RobD]

It may have been a question of fashion / style rather than harmonics? When the SMLE designers were chewing their pencils they had the new K98 and the even newer 1903 Springfield to admire. Both have barrels of 24 ins... strangely I can't hit a barn door with a K98 [can anyone?] but I find the Springfield is very accurate.

[Bruce_in_Oz]

The P-14 was built on the design of the P-13, which, in turn, was built around the outrageous .276 Enfield cartridge. That cartridge was a Cordite-fueled, rimless, almost equivalent of the 7mm Rem Mag. Pretty sure the trial troops were NOT positively impressed. And, the designers kept the blade length of the Patt '07 bayonet and fitted a new quillon to work with the exposed barrel of the P-13 / P 14. See also the stock,, which has a wrist very like a Lee Enfield. That form was to provide a positive grip whilst bayonet fighting; not for "comfort / ergonomics" whilst shooting. The "spirit of the pike" was VERY much alive and well.

The P-14 was built using the P-13 "package", with not a lot of changes. The Mk 1* was introduced to tidy up feed issues related to the change to a shorter, skinnier, RIMMED cartridge. A minor miracle it even worked at all.

The subsequent M 17 was built on the same tooling, with minor mods to allow for the .30-06 cartridge. Same barrel length, but a "proper" Mauser-style extractor.

[Daan Kemp]

The final answer, so it seems, is that the barrel length was arbitrary, a compromise to satisfy everyone and possibly no-one really. Then it remained because it worked.

In the meantime existing machinery and tooling was used in improvements for economy reasons, such as barrel diameter and taper.

[Surpmil]

Ya, some coincidences with the barrels.

The cavalry carbine was a lightened arm for the horse soldier. The lightweight barrel was slender but fully protected by stock, hand guard and nose cap. Introduced 1894.

Introduced nine years later in 1903, the muzzle diameter on the Sht.LE is much the same as the slender carbine barrel. Take a carbine barrel and stretch it by 4-1/2 inches and you have an SMLE barrel. Coincidentally also protected by a stock, hand guard and nose cap.

Then the black magic with the barrel harmonics to get the Sht.LE to shoot and compensate. Spring loaded inner center band, then a spring loaded centering shoe in the nose cap. The long Lee had none of that, just a heavy stiff barrel.

The heavy barrel created for competition use with the SMLE is basically a long Lee barrel shortened. Which coincidentally would be the same as the No.4 barrel. Eeek! Coincidentally, the barrel diameters and taper on the No.4 rifle is pretty much the same as that of a cut down long Lee.

What does all this mean? I have no idea. Just Enfield minutia.

But methinks that Enfield had some of the best engineers and designers of the time. The more I delve into what sometimes seems insignificant details, I recognize and appreciate some very clever work. The evolution of all things mechanical, materials and manufacturing processes of that time I find fascinating.

For those who haven't heard, it is reported on another forum that member "englishman_ca" passed away earlier this year. A very sad loss indeed.

The above appears to be his last post here. R.I.P.

[browningautorifle]

it is reported on another forum that member "englishman.ca" passed away earlier this year

Sad, thanks for telling us. Should be in the memorial section...?