Military zeroing of the No. 4 - inconsistent data?

[Parashooter]

It seems to me that those emphasizing ballistic differences due to cordite are ignoring the huge quantities of Mk7Z (granulated powder) ammunition produced and consumed in the past. Surely the UK military didn't obsess about instructing riflemen to adjust anything depending on what headstamp their latest box of ammo contained, no?

[Bindi2]

The Mk7z never made it to a lot of places and restricted use in others like Mk8.
The No4 rifle was issued to the RAAF in Asia and some home defence garrisons in Australia not front line troops. The only Mk7z i have seen is surplus not in quantity like several Pkts and never used it.

[Rick]

Bindi's correct with the burn rates between Cordite and modern powders they will never correlate. However on the BC's here is a difference the 2440FPS of the MkVII round is the accepted standard there has been a lot of conjecure but most agree that the MkVII projies BC is around the .467 with the 174SMK at 2200FPS BC being .499 a slight difference to be sure but it reflects on the sight settings.

Relevant to the original question, this morning over coffee I cranked various BC's through the JBM ballistics functions online. The short story is the Canadian military sighting criteria laid out in the pam Shoot To Live cannot result in a 300 yard zero when specifying 8.5" (+/- 1") MPI above POA at 100 yards. Jakester already did the same thing and pointed that out earlier today.

His question to me was along the lines of "One of these two sighting criteria that you found and provided cannot be correct". And when I looked at it after his response, I concluded that he was right that both could not be correct.

Bindi is also correct and I have stated many times get the load where you want it whether its 2440FPS or lower is your choice and do the range time to get the DOPE for your rifle as we have really beaten the skin off this horse time and again you can put into quick load what ever you please to try and figure out a decent load.

I have no idea at this point what his ultimate end game is for this. My suggestion to him when I passed on the info was that the easiest course for him would be to replace the existing Mk2 sight with a Mk1, giving him some click adjustments for elevation across the course. How that rifle came into his possession with a Mk2 sight on it must have a story behind it.

However I do feel this is not the last we will hear from this as it seems top resurface allot what needs to be done is for those wanting answers is to go to the search engine and go throuh the copious threads around this topic.

The question in the original post was why Canadian and British zeroing criteria differed so dramatically despite using the same rifle, the same backsight, and the same ammunition i.e. two inches + difference in MPI at 100 yards, both supposedly resulting in a 300 yard zero.

I can understand some zeroing in on the impossibility of what he said he was attempting to achieve with reloads; what really caught my interest was he was right to tell me the two different zeroing criteria could not both be right. It may be a purely academic question, but it was one I wanted to dig into.

At this point, having done some number crunching at JBM similar to what Jakester did, the Canadian criteria laid out in Shoot To Live simply does not work, no matter what BC you assign to MkVII ammunition.

Given the acknowledgement in the book to British and US SME's as well as Canadians i.e. Lt. Col. Stephen Johnson who had 20 years of success as one of Canada's best shooters and five times on the Bisley team, you would think that at some point SAIs (or musketry instructors at that time) would have pointed out that the zeroing criteria in the official pam simply was not correct. Shoot To Live, although I haven't thoroughly read it from cover to cover, is otherwise a pretty good pam, and its' roots certainly show up in the later editions of Shoot To Live. B-GL-382-001/PT-001, in 2004, was I think, the final version of Shoot To Live before being replaced by B-GL-382-001/PT-001 Canadian Forces Operational Shooting Program in 2007. Afghanistan apparently made the military decide some changes were required...

That aside, what his ultimate objective is, I cannot even guess. One thing he and that Lee Enfield will never lack is range time, however.

Use my load data at your own peril as I have no control how you may reload your rounds not saying youre not safe reloaders just its a sue your ar*se off world and I am not going to be held responsible for a load that is safe in my rifles but may not be in another shooters rifles. Cheers

Thanks for that; I'll pass it on if he asks for reloading data.

I doubt very much that he will be doing any reloads that get to book maximums for any powder or bullet manufacturer; having watched him reload for about two decades now, he's never shown any particular interest in trying to wring the last few fps out of any load. And that in itself might make his attempt even more difficult.

There's a few Canadian Rangers that are/were DCRA competitors and I think also shot at CAFSAC kicking around on other forums if they aren't members here as well. My curiosity about the error in Shoot To Live is now well piqued; I think I should try and track a few of them down and ask them more about the zeroing criteria they used in their patrols and in particular in preparation for CAFSAC, although Ranger issue ammunition (at least recently at the end of the No 4 service time) wasn't Mk VII or an exact equivalent.

Thanks again, CINDERS

[Bindi2]

Rick
Is that Canadian zero pamphlet built on using M7z ammo

[Rick]

Rick
Is that Canadian zero pamphlet built on using M7z ammo

It's a .pdf copy of the pam, the info page says "Prepared under direction of the Chief of the General Staff", publishing date 1945. I did searches on the word "ammunition"; there are only three instances of the word ammunition in the entire 242 pages of the book. No instances of Mark VII, M VII, etc at all. Nothing suggesting that the zeroing data might be for a specific, newer ball ammo.

To make a +8.5" at 100 yards zero work, you have to input a BC of .425 and a muzzle velocity of 2200 fps to have that result in a 300 yard zero.

[Rick]

browningautorifle had a post here where he pointed out that in recent memory, the Canadians have not taught shooting with bayonet fixed. Perhaps the occasional course had course staff that had a few minutes of extra time to fire a group at 100 yards with bayonet fixed in order to see the results, but that's about it. Like he also said, there was about as much time devoted to that as with shooting wearing your NBCW bunny suit and mask.

I don't remember any of the earlier Shoot To Live pams, circa the C1 prior to the SARP that replaced the C1 with the C7, that specified any firing (particularly zeroing) being done with bayonets fixed. The earliest digital pam I have (about 2003) only mentions that bayonet fixed results in lower points of impact, nothing else. That continues with the latest versions of what is now the Canadian Forces Operational Shooting Program.

[Bindi2]

The pam. as you say don't define the ammo you will have to look at the ammo spec sheets and see if or when Canada changed to Mk7z.

[Rick]

The pam. as you say don't define the ammo you will have to look at the ammo spec sheets and see if or when Canada changed to Mk7z.

I think that would fall more into the realm of the military historians and collectors here; and you'd probably have to have some reach into DND as well as the desire to know.

For the purposes of my original question after it appeared that at least one of the zeroing criteria had to be wrong, there is simply no way that the Canadian military pam's instructions on zeroing the No4 Mk1 in 1945 can be correct. Even with some other variant of the ball round.

As I related above, you have to cut muzzle velocity back about 250 fps, and the ballistic coefficient back to being in the low .400's before a +8.5" zero at 100 yards is at point of aim at 300 yards.

I wonder what was going through the minds of those Canadian musketry instructors at the battle schools and all those infantry regiments back in 1945, 1946, 1947, etc as that pam was pushed out to the schools and they attempted to zero rifles using the specified criteria? And, I assume, they probably had a different zeroing criteria during the war years 1939-1945 prior to the pam being published and distributed.

Locally, I have no doubt that many would have chucked the pam and figured out their own procedure for properly zeroing the assorted backsights within the ranks. But there must have been a few that started sending dingers up the line asking questions and pointing out that the official military pam on zeroing the issue rifle was wrong.

I will see if I can track down a few of the Canadian Rangers that are on other forums and ask what they remember of anything resembling a pam or a similar document specifying zeroing criteria for their Lee Enfields. If I come up with anything from that angle, I'll post it up here.

Thanks Bindi

[Rick]

It seems to me that those emphasizing ballistic differences due to cordite are ignoring the huge quantities of Mk7Z (granulated powder) ammunition produced and consumed in the past.

Just musing here a bit Parashooter, while having my morning coffee to kick start my brain.

How much of the differences in BC, whether using a G1 or G7 model, giving the Mk VII it's ballistic track (that is so far apparently not matched) are due to the construction design and materials used in that bullet that have nothing to do with the propellant being used? A cup and core bullet of nothing but lead and a copper jacket is a very different thing in comparison to a Mk VII ball round.

[Parashooter]

I believe Mk7 and Mk7z use the same projectile. It's Mk8z that's different.