No. 4 Rifle; Zeroing Instructions Data Inconsistency?

[Rick]

As I'm once again getting ready to make our range my second home as the last of the snow disappears, I am again distracted by the zeroing data for the No. 4 rifle being inconsistent when looking at the Canadian pams versus the Brit/Aussie pams that I have on hand.

I know this is mostly academic at this point, as Mk VII ammunition has become pretty much as easy to find as unicorn poop. But to summarize what is aggravating me so much, the Canadian pam Shoot To Live from 1945 is my Canadian resource.

The later 1991 and 2002 Canadian pams for the rifle concerning operating instructions (curiously) have no references to zeroing instructions. (As well, I thought the Canadian military coming up with "Shoot To Live" as the appropriate title for training infantry to kill with the rifle was a product of modern Canadian governments).

Because all training centres have not the complete facilities for zeroing rifles
at 100 yards, the methods of zeroing have been made available for both the
30-yard and 100-yard targets, although the latter is better. In either one
if you aim precisely at the point of aim, the sights should cause the bullets to
strike the 30-yard target 2.25 inches above the auxiliary aiming mark's base
and if it were to continue to the 100-yard target it would strike 8.5 inches
above the auxiliary aiming mark's base.

Should it continue on to the 300-yard target in the distance, it should fall
directly upon the aiming point.

The Brit's Precis No. SA/19A from 1950:

In the case of Rifle No. 4 fitted with a Mk 2 Backsight, the apertures of which
are sighted for 300 and 600 yards, the Rifle will be zeroed using the 300 yard
yard aperture with a Bayonet fixed.

So: the wartime Canadian pam says the No. 4 rifle with a 300 yard aperture will have a POI +8.5" at 100 yards when zeroed. British pams say a No. 4 rifle with a 300 yard aperture will have a POI of +6.0" at 100 yards when zeroed.

+8.5" versus +6.0" at 100 yards - that's a HUGE difference. Doing some quick tests in a ballistic calculator shows that the zeroing information from the Brit pams is almost certainly correct, while there's no way the Canadian information can be correct.

Am I missing something here in what I see as such a huge discrepancy?

I would think Canadian infantry NCO's assigned to be SAIs at the battle schools, taking recruits through the process of zeroing their rifles would immediately realize that using this data to zero at 100 yards did not get the expected correct results when firing afterwards at 300 yards.

And is there a Canadian pam for the No. 4 rifle published after WWII that contains zeroing instructions that I'm not aware of?

[Alan de Enfield]

Could it simply be the method of training ?

The Brits used the 6 o'clock hold for the POA (3" below the 'bull' ?)

From your picture the Canadians use the 'bull' for POA

[Surpmil]

Without going and getting "Shoot to Live" off the shelf, does it describe zeroing as to be done with the bayonet fixed as you state the UK pamphlet does? If not, that might account for the difference in MPI vs. POA?

I'll see if I can get access to a post-war Canadian manual that describes zeroing the No.4.

[muffett.2008]

Or maybe it's the difference between the Brit Cordite round and the Canadian Nitro Cellulous one.

[Rick]

I'll try this reply on my phone while cooling my heals in a waiting room.

First, thanks for the input:

First, both pams require rifles be zeroed with bayonet affixed, and rear sight be used with 300 yard aperture. (After 30 years in the military as a Death Tech, much of that on regimental rifle teams and a lifelong recreational and competitive shooter, I have always been curious as to why you would zero at 300 yards with bayonet affixed. Not much hand to hand quarreling that goes on at those distances. The shift of POI at ranges where you would have bayonet fixed would be irrelevant. We didn't zero our FNs in that manner)

Without my wartime Brit and Aussie Pam's here with me, from memory they specify the same data for zeroing as the 1950 Armourer's data. So it wouldn't appear as though any difference between cordite and smokeless would be a confounding factor.

Furthermore, if the same MkVII ball round leaves the muzzle at the same velocity, whether it got that MV from cordite or smokeless isnt going to make much difference.

Aside from all that, if there's a .pdf copy of a Canadian Pam's between the 1945 "Shoot To Live" and the 1991 verson of the No.4 Pam's which I have, I would like to see it out of curiosity.

I'm equally curious that there isn't any zeroing sections in the 1991 and followup 2002 pams.

[Bindi2]

Rick
I have never been able to match Cordite and Nitro loads on the range chart with the rifle sight markings at the same FPS. We had to make our own dope sheets.

[Rick]

I have never been able to match Cordite and Nitro loads on the range chart with the rifle sight markings at the same FPS. We had to make our own dope sheets

Unless I've forgotten, I don't think we were ever issued Mk VII ammunition from the DCRA that was cordite; I imagine it was all used up by that point, 30 years after the WWII ended and 20 years after Korea. By the time I enlisted, the No.4 had been replaced by the C1 FN FAL, so I had no military experience with the rifle.

That aside, we know you have to adjust your come-ups at longer ranges due to the differences between lots of ammunition. But perhaps more specific to the question, a couple of things:

1. With all the detail provided in the Brit military pam, if there was a significant amount of ballistic difference for the average infantryman between the original cordite and then after the ammunition was loaded with smokeless, I would expect that at some point in the Armourer's pam there would have been a notation on zeroing differences when cordite was being used and when smokeless was used. What pams and material I have read is silent on any significant differences.

2. A 2.5 MOA difference at 100 yards between the two sets of zeroing data is an enormous amount that I doubt the difference between cordite and smokeless could potentially explain.

3. If you try getting a grip on how such differences could be possible, pick your ballistics software of choice, give the Mk VII round a G1 B.C. of about .467 and a MV of about 2440 fps. Then look at the manipulations to muzzle velocity, etc you have to make in order to produce a ballistic result where POA=POI at 300 yards - and a height above line of sight at 100 yards that is 8.5".

On the other hand, the zeroing data provided in the Armourer's precis is pretty much bang on when fed into a ballistics calculator. The Canadian data in the 1945 Shoot To Live just does not fit.

My assumption is that I am missing something, somewhere, but the Canadian zeroing data just doesn't fit.

[Bindi2]

The bit you are missing is the difference in barrel harmonics between the two charges.

[Rick]

The bit you are missing is the difference in barrel harmonics between the two charges.

Thanks for the suggestion. But if that's so, the authors at Higher Niner of the various nations' pams, the 1950 Armourers' Precis, Reynolds, et al similarly also didn't notice the difference in barrel harmonics between the two charges in any version of the rifle.

None noticed sufficiently to even making mention of a significant difference in barrel harmonics between Cordite and NC loads, resulting in conflicting different zeroing data being required as in the Canadian Shoot To Live, based on whichever type of propellant was loaded.

As NC apparently was first introduced at the end of WW 1, and Cordite loaded ammunition was still in the supply system through WWII and then Korea, there is no certainty that a Commonwealth nation whose troops were in battle could be exclusively supplied with either Cordite or NC based ball ammunition to match whatever the troops' rifles were zeroed with prior to being sent into battle.

And a 2.5+/- MOA difference in zeroing is well over the difference of a single change in front sight blade height. So I would presume that Higher Niner, the ones developing and updating the pams throughout the service life of the rifle would have taken such a significant difference into account - even if only a simple notation somewhere within at least one of those publications, whatever version of the Lee Enfield it was attached to.

To fuel my academic curiosity about the two very different zeroing specifications, I have a range document from inside the Canadian Rangers with this related to zeroing their No.4 rifles:

LE Sites are calibrated to 174gr Spitzer Point Flat Base Mk7 Ammunition. Rangers are issued 175gr Spitzer Point Boat Tail Mk8Z Ammunition... Desired Point of Impact: 8.5" above the point of aim.

If Mk8z ammunition manufactured by IVI (or whoever in Canada) in the 1980's for the Rangers is in fact correct, at the suggested velocities for Mk8z ball ammunition, you would expect an even flatter ballistic parabola, and an even LOWER height above point of aim at 100 yards to obtain POA=POI at 300 yards.

[there's some confounding factors in these instructions in that the paper instructs zeroing at 100 meters, not yards, for a zero at 300 meters, not yards. And of course, with their issue sights calibrated for yards, I haven't bothered yet to see if a ballistic calculator says that a +8.5" POI works when sighting using metric instead of yards. I think a calculation of those ballistics, even with 300 meters being longer than 300 yards, you will still be lower than +8.5" at 100 meters to be zeroed with the 300 yard aperture at 300 meters.]

A shooting/rifle obsessed friend just retired as the RSM of his unit, and promptly joined the Canadian Ranger patrol nearest him. The Lee Enfield has been gone for a couple of years now, but I'm going to ask Gary if he can prowl what they have in the way of pams to see if they have anything there that relates to thus point of curiosity.

I also know Russ Meades as an acquaintance from way back in the day when he arrived here from the UK and enlisted in the Canadian military. Russ was pretty keen on shooting back in the day, and he ended his career decades later as the officer in charge of the Canadian Rangers; perhaps he can shed any light on it.

And finally, my brother retired from 30 years working at BATUS as a civilian whose working days were spent working beside British REMEs on the Challenger tanks and everything else mechanical that moved. He told me yesterday that one of the REMEs who stayed here is a Lee Enfield obsessed rifle nut, a good friend of his who I helped secure the recovery of a Land Rover (but why????), found multiple NATO documents on their military version of the DWAN that he printed out, which might relate to zeroing specifications. So perhaps there is something there as well...

Again, at this point it's purely an academic curiosity now that all the worthwhile Mk VII seems to have disappeared forever. But I do find a 2.5 MOA difference at 100 yards while zeroing these rifles to be interesting, with the Canadian disagreement with the other Commonwealth pams relating to zeroing this rifle.

Thanks again for the suggestions!

[CINDERS]

All the bets are off using the MKVII data simply because of A) Powder burn rates and more importantly the higher BC projectiles I've faffed around with this no end using MKVII data and trying to emulate the trajectory mid flight of SMK's (Velocity Rates V's Trajectory)to get the hit at the desired range.

I can tell you I used Litz's program, Load Data program with lots of shooting which led me to the conclusion that I just settled on a load that pretty much matched the 2440FPS of MKVII rounds and then shot the ranges we do in all types of weather to get the DOPE.
You'll find the correlation when using high BC projies like the SMK your having to dial in @50+ yards (They fly flatter than MKVII's) more onto the elevation to get a hit but the better catch here is wind drift is not as pronounced with the new projectiles.
I've lucked onto 400 Highland 174's these I have been told emulate pretty much the MKVII flight characteristics Sellier & Bellot use them in factory loadings AFAIK.
Along with 1500 SMK's, I also luckily have 500 TAIPAN .312" FBHP's which are a very rare, seeing as Malcolm Bone has probably passed on & the new owner gave it away after break in's & theft's.

So the best thing is to try and get your new projectiles your going to have to do the range time like we all did, in fact 3 weeks ago I watched one of our shooters off a bench at 500M using old MKVII ammo out of a scoped No.4 (Not a T) with the shots going in the general vicinity of the bull!
So my load I settled on after the adventure was 46 Gns of AR-2209 (H414-H4350, IMR 4350) Fed - Match primer, AMP annealed RP case, I set the 174 Gn SMK to the COAL of a POF 1967 MKVII round using the Ogive may had had the round to long for the mag. (No responsibility with others using this load data)
I have won comps with this load most notable one was the 2016 invitational to the SASR range at Swanbourne multi positions over 300-200-100 yards against 40 other shooters I also won the 600 yard shoot with my 308 APRS as well on a Fig.11 against the same amount of shooters.
Shot a perfect 10 round 50 points however it was a very hot day we walked everywhere I neglected to manage my water & electrolytes properly and stuffed up with heat stress on the last match for possible a triple win!

So the good thing here is you are going to do lotsa shooting.