Morris calibre sight adaptor ?

An unusual, but structurally simple pressed steel device, this little adaptor is something of a conundrum. Marked "M 4" and ".297/.230", it would appear to be for clipping to the sight of a parent rifle when that rifle has been fitted with a sub-calibre Morris Tube, thus adjusting the calibration by raising the point of impact (POI) for the lower power round.

The well-known Bisley shot who came across the unit has tried it for fit to a number of likely rifles, and, after making up a replica to the dimensions kindly given to us by him, we have confirmed his initial assessment by repeating the search.

He found that the unit best fitted the tangent leaf of a Lee-Enfield No.1 Mk.1 (S.M.L.E.), which has a groove cut either side, in which the elevation slide runs. The spring-steel adaptor clips into these grooves, and can be locked back against the greater width of the windage block - the slide then being moved back against it, holding it perfectly in place.

And viewed from above

An S.M.L.E. Morris Tube not being available, the unit is here shown fitted to a .303 parent No.1 Mk.1 rifle that has a .22RF aiming tube fitted, and the appropriately modified rimfire bolt.

The outward appearance is therefore similar to that of an "MT" rifle,

but showing a smaller chamber in the receiver, and rimfire bolt-head.

 

On an "MT'" (Morris Tube) rifle the adaptor would look as this from the front .........

 

......... and as this from the rear.

 

Close-up, the adaptor shows the significant height increase from the standard tangent sight.

This is in the order of 0.400".

If clipped in front of the elevation slide, the tangent leaf can be left at its lowest setting.

 

But is free to slide forward if affected by the recoil of the rifle when fired.

Even the recoil from a Morris round could be sufficient to do this.

 

The rear-sight of this .22RF converted Pattern'14 training rifle

has a 25 yard mark stamped at the 300 yard full-bore .303CF setting.

We do not have trajectory figures for the .297/.230 CF Morris cartridge,

but assume it to be not hugely different from that of the .22 Long Rifle round.

Thus somewhere near a three-hundred yard setting would be suitable for use on a miniature rifle range.

The adaptor, if mounted ahead of the slide at this setting, would significantly raise the point of impact.

However, when fitted more securely behind the slide, the tangent leaf is forced up to nearly the 800 yard position.

With the added increase in rear-sight notch height of approximately 0.400 inches,

plus the additional rise of the leaf from the 25 yard setting to 775 yards,

the height of the notch would increase by around 0.650".

Thus the adaptor would produce a significant rise in the point of impact, which we have yet discover.

 

The great elevation can be seen in the two adjacent images.

 

One other rifle to which the adaptor could possibly have been fitted is the War Office Pattern 1906 Miniature Rifle.

The unit is an almost perfect sliding fit over the tangent rear-sight's windage block;

although our replica, perhaps made too tight in channel height,

would not quite slide into position by a few 'thou'.

 

 

But this seems a rather unlikely employment of the adaptor.

 

Indeed, the question here would be - why would a .297/.230 sight adaptor be required on a War Office Pattern Miniature Rifle? The rifles were anyway available in Morris calibre by special order. Probably such rifles were still fitted with the standard .22RF calibrated tangent sight, as it would no doubt have been prohibitively costly to produce a .297/.230 leaf especially for what were certainly very low production numbers. It is also not likely that the trajectories of the .22RF and Morris rounds differed sufficiently at miniature range distances to warrant any change in calibration.

In any event, with the adaptor fitted to the War Office rifle, the lift in notch height is about 0.190", probably rendering the POI about a quarter-of-a-mile away! As can be seen in the photographs above, the standard leaf was already calibrated up to 200 yards - usually considered to be the maximum practical accurate range for the .22 Long Rifle rimfire cartridge.

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There is a possible reason for such elevation increases being required on a Morris calibre rifle.

Thus far, the most reasonable explanation for the adaptor is that it was perhaps a harmonising device for Landscape Targetry, in which the firer aimed at a printed landscape target which had a plain "sky screen", usually about 27" above, that took the bullet strikes. This kept the expensively printed landscape target intact. Scoring was achieved using a pendulum device the length of the vertical height diffference between the Point of Aim and the POI. Details of this system can be found HERE.

To that end, it could perhaps have been used on either of the above rifles,

but Morris calibre War Office rifles were not much in use and, as far as we know,

not issued to schools or military units, the .22 rimfire round being a more economic proposition.

The respective lifts in the POI for the Morris round on an SMLE adaptor have yet to be tested,

and we are anyway only in a position to trial the adaptor

using the .22 Pattern '14 rifle or a .22 RF Aiming Tube in an SMLE.

A lift of around 27 inches at 25 yards would potentially go some way to prove the point.

The more recent .22RF training versions of the No.4 rifle, more usually the Lee-Enfield Rifle No.8,

but also the Royal Air Force's Lee-Enfield Rifle No.7,

and the Royal Navy's Rifle N.9, when fitted with the harmonisation sight, provide a raise in elevation

from the normal horizontal POI at 25 yards to the required 27" rise in POI for landscape targetry,

with an increase in elevation slide height of 0.8125", as shown in the image below.

 

This 0.8125" rise is 25% greater than the equivalent 0.650" figure for the Morris adaptor on the .22 Pattern '14 rifle, but without trajectory comparisons for the .22LR and .297/.230 Morris Long cartridges it is not possible to confirm whether the Morris adaptor would provide sufficient lift in the POI. Additionally, the height difference between a very early Landscape target and its 'Sky Screen" has to be confirmed as being the same 27" as the WW2 targetry, but is believed to have been so.

The WWII Musketry Regulations indicated that the .22RF SMLE, the Lee-Enfield No.2 Mk.IV*, could be used harmonised at 25 yards, with the tangent leaf elevation slide set to 1,400 yards.

Below: the .22 No.2 MkIV* with sight harmonised

The Musketry Regulations went on to say that "harmonized firing is also possible with No. 4, but not No. 5, Rifles on a 25 yards range; set the sights at 1,300; have your horizontal lines 23 and 25 inches above the bottom of the aiming mark; and use a measuring rod 24 inches long.'

Whether the Morris adaptor's 0.650" notch rise on a .22 Pattern '14 rifle would have provided a sufficient lift in elevation to put the Morris projectile either 24" or 27" above the normal horizontal level when clipped in behind the elevation slide set at 775 yards we have yet to discover..

But bore-sighting the .22RF No.1 Mk.1 Pattern '14, with the adaptor sighted on a Point of Aim at 25 yards, put the bore line to a point approximately 32 inches above the POA; so that was fairly close, without knowing the precise fall of shot of the Morris projectile at that distance.

In the event, firing the .22 rifle at the diagram in the image on the right on a 25 yard indoor range, with the foresight blade taking a six-o'clock aim on the black, resulted in the "group" shown at almost precisely 27" above the POA.

The first shot, and three others, produced the 4-shot group at that height.

Probably the near eighty-year-old Mk.1 eyeball over open sights, and the misting of spectacles on the chilly range, were the cause of the other six spread shots.

The fall of shot of the .22RF bullet is therefore approximately 5 inches at 25 yards.

That this rifle, converted around a hundred years ago, can still produce one-hole groups is testament to the quality of barrel work of the Parker company, and their Parkerifling system.

If a keen collector and shooter with a Lee-Enfield No.1 Mk.1 and a .297/.230" Morris tube would care to make up an adaptor and range test the change in POI at 25 yards with it fitted, we would be delighted to know the result.

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It has been assumed that the most likely manufacturer of the adaptor was one of the Parker or Parker-Hale companies, but the pressing does not carry any of the usual "AGP" or "Parker-Hale" stamps.

We have also thus far been unable to find any reference to the adaptor in either the abridged List of Changes, or Patent Abridgements for the likely period post 1900.

The "M" and "4" marks on the device are also as yet unrecognised, although there has been a suggestion that the "4" has been used elsewhere to represent a .303CF calibre arm.

So it is possible that they refer to Morris and the then Service calibre.

Should you have knowledge of all this, or be aware that we have been barking up the wrong tree, please let us know! It is sadly unlikely that anyone remains alive who used, or knew of the device first hand.

 

See also: Landscape Targetry