Accuracy Standards for No. 4 Mk 2 Rifles

[cprher]

A while back I stumbled upon a discussion (or article) that discussed the accuracy standards the No. 4 Mk 2 rifle had to pass to be accepted. It was a rectangle, taller than it was wide, shot at a specific distance(s), and X out of Y shots had to land inside that rectangle using ball ammo. The discussion covered the standard at a variety of distances not just one.

Does anyone have a link to that discussion, or can point me in the right direction?

Keith

Information

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[Mk VII]

All rifles were tested in a mechanical rest and had to group four out of five shots in a 1.5" x 1" rectangle at 100ft.
One in ten, and any doubtful ones, were tested again at 600yds and all ten shots had to hit an 18" square. [1955 Pamphlet No.3]

[Peter Laidler]

This covered ALL mks of the rifle and not just the Mk2.

[cprher]

Just so you know why it's of interest. I belong to the FAL Files discussion forum as well and a continual dialog revolves around "why is the FAL so inaccurate". To many on the forum, the FAL should be at least able of 2MOA. Others believe it's not capable of better than 3-4MOA. I shared the standard that Mk VII was kind enough to provide to give those on FAL Files a bit of a different perspective. I'll share with you what their reaction is.
Keith

[Frederick303]

I think I has to do with a lot of folks not having any experience of statistical analysis or a feel for sample size. So if a fellow gets on 5 shot group of 1.5 inches he assume the rifle can always do that, rather than that might be the smallest 5 shot group of five, 5-shot groups, the largest being 4.2 inches. A 3 to 1 variance is not outside of what one can expect if testing in that manner.

To target shooters, who generally do not fire any group of less than ten shots and care about the typical group size, I note the expectations are not so exacting.

[Peter Laidler]

This is from the bible.
The rifle will be test fired from a mechanical rest where available or by the best shot at 25 yards. Left wrist supported over cover (a sandbag). Two warming shots to be fired into the bank and sighting-in shots as necessary. 5 shots at the aiming mark. ALL 5 shots WILL inside or cutting a superimposed rectangle 1" horizontal x 1.5" vertical.

The backsight will be set to 200 and the Mk2 backsight will be set to 300 yards and the bayonet will be fixed

The correct position of the MPI in relation to the point of aim with the Mk1, 3 and 4 sight WILL be 3/4" above. Mk2 sight 1.5" above
Permissable variation - vertical +/- .5". Lateral - NIL
Limit of deflection of foresight: edge of blade base at edge of foresight housing in block
Rifles failing to conform to these criteria at Unit level will be sent to Field or Base workshops

At Field or Base workshop the differences are:
Permissable variation - vertical 3/8"
Lateral dajustment of foresight limited to .03" of centre
Variation of foresights limited to between -.015" (-.030" at unit) and +.075" (.090" at unit)

Rifles failing to conform to these criteria will be condemned and reduced to salvage with the range accuracy diagram attached to the condemnation certificate. Later changed so that a drawn representation would suffice

No hypothesis there, just straight from the bible. Note that this applies to the No4T from iron sights too. (less the Mk2,3 and 4 types of course)

[muffett.2008]

EMEI Weapon A 263-1 Accuracy standards for the OZ L1A1 were..... Target- plain white screen with a 25mm square aiming mark, range 25m.
POA centre of bottom edge, POI 13mm below aiming mark(tolerance vertical 12mm above or below, horizontal nil)
5 Rounds to be contained within or cutting a 50mm diameter circle.

[cprher]

EMEI Weapon A 263-1 Accuracy standards for the OZ L1A1 were..... Target- plain white screen with a 25mm square aiming mark, range 25m.
POA centre of bottom edge, POI 13mm below aiming mark(tolerance vertical 12mm above or below, horizontal nil)
5 Rounds to be contained within or cutting a 50mm diameter circle.

That sounds like about 8MOA. I imagine, since they don't mention machine rest, that this is shot from a prone unsupported position.

Keith

[Peter Laidler]

We don't range or accuracy test from the unsupported position. There is far too much human error