Miniature conversions

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"BACK FROM THE WAR "

 

.................................................or .......MINIATURE TRAINERS ?

 

Below is an extract from Richard Arnold's - BOOK of the .22" - 1962

This section relates to .22" training arms and conversions for their full-bore examples.

 

The units dealt with on this page are those which will fit to the parent full-bore arm
allowing temporary use with miniature cartridges.

Two types specifically referred to in the text of the following excerpt are:

The Williams Floating Chamber and The Morris and Aiming Tubes

Taken from THE BOOK OF THE ·22 Richard Arnold 1962 HISTORICAL OUTLINE

Alongside the development of the ·22 rifle and its ammunition there have been inventions, some excellent, some useful, some downright impractical, relating to the · 22 as a training arm, as an ancillary weapon, or as an accessory to it. Two remarkable developments standout: one perfected in the United States and one in Great Britain. The first, the floating chamber principle, was the invention of Marshall Williams, who devised it whilst serving a sentence in a United States penitentiary for an offence during the days of Prohibition. For sometime the American forces had been using the Colt ·45 semi-automatic pistol for training their personnel, but the cost of ammunition presented problems. The use of a ·22 pistol, built like the ·45, did not solve the problem. Smaller calibre ammunition made it more economic but without the buck of a heavy pistol in recoil, the use of a ·22 did not assist much in preparing a nervous recruit to handle the heavier handgun. Williams devised the floating chamber in which the gas produced from the fired cartridge of a ·22 was allowed to escape at the front of the chamber. This gas thrust against the area of the cartridge base plus the considerably larger area of the chamber front. The backward action of the gases was therefore considerably increased, the thrust of the weapon in recoil greater in consequence. The net result was that a ·22 pistol was built giving the same recoil as the larger ·45.
The next step was the incorporation of the floating chamber using the ·22 long rifle cartridge into the Browning machine-gun. In addition to building floating ·22 chambers for many semi-automatic rifles, Williams designed the short-stroke piston for the Garand automatic carbine, but that is outside the scope of a brief historical survey of the ·22.
Improvements have been made on the original Morris tube invention - ·22-calibre adapters have been made to insert into the barrels of shotguns, whilst Parker-Hale Ltd of Birmingham brought out a really first-class adapter for the Webley and Scott ·455 calibre service revolver. This, though it did not incorporate any floating chamber principle to increase recoil, was none the less a great aid in training the pistolmen in shooting. It was made in two patterns, as a single-shot adapter, in which the cylinder was removed from the pistol so that it was fired in skeleton form, or complete with a special cylinder chambered for the ·22 rim-fire cartridge. This adapter was also manufactured for the ·38-calibre Enfield Service Revolver
These adapters are still in use today and used fairly extensively. They do not affect the accuracy of the revolvers and are guaranteed to shoot into a 3/4 - inch group at 20 yards, which is better than the handler can claim.
The most remarkable development was, however, the principle, derived from the Morris Tube, by Mr. A. T. C. Hale in introducing the system which he called 'Parker-rifling'. In this, worn barrels are bored out and a new rifled tube is inserted. Nor is this confined to worn barrels, for many larger bores, such as ·303 service rifles, can be converted to ·22 rifles by this process. It is an economical way of making a first-class sporting arm from an obsolete military one. It is not suitable for military cartridges, nor for high-power sporting cartridges, though Parker-rifling is suitable for the ·22 Hornet. It seems strange that many a useless high-power, large-calibre weapon should become a small ·22-calibre arm capable of extremely accurate shooting, yet there it is. Commonplace the ·22 may be, yet its history is colourful and proud: whatever the future may hold in the development of firearms and ammunition, the little ·22 occupies an important position in the history of firearms as a whole. Large-bore riflemen may hold it in contempt, but most successful riflemen start with this weapon, while for military purposes its utility in training has been proved time and time again.
From the standpoint of the ordinary shooter, the ·22-calibre rifle is the most important in the world and there is a lot to be said for their attitude. Perhaps, speaking of Great Britain alone with its growing numbers of riflemen, one could parody the old song and say: 'Four thousand rifle clubs can't be wrong!'

 

Richard Arnold could hardly have foreseen the change in climate that would take place only thirty-odd years after he wrote this piece in 1962.

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The Morris and Aiming Tubes:

Below are images of a Martini Metford Carbine converted for use with a .297"/230" Morris miniature cartridge.

Originally an 1874 Enfield manufactured Martini Henry Carbine II, its markings show it to have been converted initially to a Martini Metford Carbine .303" III in 1893. Unlike the later .22" Aiming Tube for the S.M.L.E., which is in one piece and slides into the bore from the rear with the bolt removed, this is not possible with the Martini action. Instead, the unit is made in two pieces. The rifled tube is fitted from the muzzle, and the chamber section shown above is fitted via the receiver. A locking tool is used to hold the Morris chamber and prevent it from turning whilst the rifled tube is screwed into it from the muzzle. The larger brass locking nut is then screwed up to the muzzle crown with a leather washer in between.

Its final conversion markings of "MT" on the knox-form and on the RHS of the butt stock are illustrated below.

The following image illustrates the Long and the Short of the Morris cartridge, so to speak.

The rifle shown is chambered for the Long cartridge. The flanged sliding extractor of the Morris chamber is pulled back by the original full-bore extractor as if it were a .303" cartridge.

The Williams floating chamber:

This unit is not strictly under the remit of these pages, not being a rifle adapter, but it is a remarkable design and worthy of mention.

Below is a facsimile of the brochure advertising the .22" Colt Ace pistol. The system was more usually sold as a conversion (adapter) unit for the Colt 1911 .455 or .45 Automatic. This adapter was probably the most common usage of the Williams floating chamber.

Below are images of the .22" barrel and floating chamber. The first shows the chamber section slid from the barrel. The second shows the chamber in position before firing, closed up against the rear of the barrel. The third image shows the chamber slid back against the rear of the slot in the barrel lug after firing. The impact at this point provides a level of recoil that would otherwise be missing from a nomally chambered .22"calibre arm. The system was also used in various machine gun miniature conversions.

Beneath is an image of the marking on the LHS of the slide and another of the barrel and chamber in position in the slide. The calibre marks and the split between barrel and chamber are the only give away of the conversion apart from the slide notation and a rather undersize hole at the muzzle.

 

 

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