2 groove barrels..

[buffdog]

In his book "The Lee-Enfield Rifle", Major E.G.B Reynolds has the following to say about Wartime manufacture of rifles.

"Barrel making was another serious "bottleneck" in rifle manufacture, and efforts were made to simplify the process. In May, 1941, trials were carried out with barrels having TWO grooves instead of the normal FIVE."

He goes on to comment on accuracy tests and bore fouling. A number of two groove barrels were fitted to No.1 Mk.III rifles and were tested against regular production rifles with five groove barrels. Ten rounds were fired in one minute with each rifle, then shot for accuracy while still hot. This continued in cycles of fifty rounds until 500 rounds were shot through each rifle.

"There was no appreciable difference between the two forms of rifling in either accuracy or barrel wear." and "It was decided to adopt the two-grove abrrel as an alternative form of rifling for all .303 rifles."

Also, permission was given if it helped the manufacturer to use Four groove barrels for No. 1 rifles, and some were made for No. 4 rifles.

In May, 1942, trials were made with THREE groove barrels, and after 5000 rounds had be fired through them, accuracy was still good.

( Source: Reynolds --The Lee-Enfield Rifle -- Page 158 )

Since Savage or Long Branch would not have taken it upon themselves to change specifications of the No.4 rifles without permission from the British, this leaves the question of the Springfield rifle.

The modified Springfield 03A3 was originally developed for the British. When the Japanese brought the U.S. into the war in December, 1941, the focus changed to the 30.06 Calibre for the U.S. military. It would appear that the U.S. Military, in order to speed up production, adopted the British idea of TWO groove barrels. I have a TWO groove Enfield 1917 in 30.06 with a Johnson replacement barrel, but it is dated 1943.

So, I hope this answers the question. It appears the first large scale use of Two groove military barrels was the British, in May, 1941. ( This does not take into account Muzzleloading rifles )

Information

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[Bob S]

The modified Springfield 03A3 was originally developed for the British. When the Japanese brought the U.S. into the war in December, 1941, the focus changed to the 30.06 Calibre for the U.S. military. It would appear that the U.S. Military, in order to speed up production, adopted the British idea of TWO groove barrels. I have a TWO groove Enfield 1917 in 30.06 with a Johnson replacement barrel, but it is dated 1943.

The 03A3 was not developed for the British: it resulted from a number of production shortcuts that were developed at Remington during M1903 production for the US, long after the British lost interest in a modified M1903 (not A3) in favor of No. 4 production at Savage.

The US two groove barrels leveraged off of the British research, however. US drawings and specifications were changed to require two groove barrels for all US rifles, under the mistaken assumption that this would speed production in all cases. The Law of Unintended Consequences applies. High Standard, who was making barrels for Smith Corona (Smith Corona did not make any barrels) and had a contract for spare barrels for the M1903 and the M1917, notified Ordnance that the change to two groove rifling would involve a considerable delay in production for the development of a two-groove broach that would function without excessive chatter and resultant damage to bores. High Standard was rifling with the broach, or "button" method, which is much, much faster than cut rifling. The US Ordnance failed to recognize that the change to two groove rifling would save production time and costs only if the barrels were rifled with the cut-rifling method. The drawings and specs were quickly changed to require two-groove rifling only where it would result in cost and time savings. That allowed Remington to make 2 groove barrels, and High Standard to continue broaching four grooves. Remington was transitioning to broaching during the latter part of 03A3 production, and some later "spare" barrels that Remington provided in its second contract for 03A3 spares are four groove broached barrels.

You need to be careful about the "late" four groove barrels, though. There are many late Remington 2 groove barrels that were "re-rifled" to four grooves in order to fetch a higher price from unsuspecting milsurp fans in the mistaken impression that four groove barrels are somehow "better", and therefore should command a much higher price. SARCO is one that has been selling the bogus four-groove 03A3 barrels. You can usually tell if they have been altered by careful examination of the bore. The finish in the opposite grooves will be noticably different; the lands may not be of uniform width; and if you slug the bore and measure the groove diameter of the pair of opposite grooves, you may find that they differ by as much as .001"

Nearly all Smith Corona barrels were made by High Standard, but marked "SC". Some early six-groove barrels were made from commercial blanks that were accepted due to the extreme need, and the necessity for H-S to have a four-groove broach designed and made to the US military specs. It has been speculated that Savage also may have provided some barrels for S-C 03A3 production. Until recently, two-groove barrels marked "SC" were unknown. In the past ten years a few have surfaced; I have seen two that I feel are authentic ... that is, the markings do not appear to be altered. The origin of the S-C two groove barrels remains a mystery and is the subject of continuing debate among "advanced" collectors. Me, I'm not a "collector", I'm a shooter.

Resp'y,
Bob S.