No. 4 Rifle; Zeroing Instructions Data Inconsistency?

[Surpmil]

Plainly, nobody needs to be qualified as a mathematician nor a career in external ballistics to realize that it is quite impossible to have the same bullet, leaving the same rifle with the same sights and sight radius, at the same muzzle velocity, take two completely different paths with 2.5 MOA of variation, from the same point of firing to the same point of impact at the same range.

Why in your opinion was a variation of 2 MOA at 100 yards mentioned in STL as acceptable and possible?

Would a similar variation be likely to exist in ammo used for this purpose in the British Army at that time?

[Rick]

Why in your opinion was a variation of 2 MOA at 100 yards mentioned in STL as acceptable and possible?

Right back at you:

Why in your opinion does that variation at 100 yards in the Canadian 1945 Shoot To Live become an explanation for DELIBERATELY sighting in with a 2.5 MOA error at 100 yards - an error that then increases the error of the POI versus POI as the ranges increase after that?

An error, BTW, that wasn't used in sighting in by Canadians BEFORE the 1945 pam was published, if that 2 MOA variation is the explanation.

And also BTW, an error that the Brits chose not to change their zeroing procedures to emulate the Canadian pam after it was introduced?

[Rick]

Being deprived of my computer and data files has been helpful in allowing serendipity to lend a hand.

I was talking with a new acquaintance here who immigrated (well, the US government is immigrating him) from Australia, a P.Eng who has a contract with the Navy's advanced warfare guys on both the west and east coast to build them... something. Flathead Lake met his requirements for deep water for whatever he's doing. He mentioned that his father used to talk and drink about the fighting on the Buna Trail in Papua New Guinea while he was alive.

I got curious because my Uncle Bill flew Beaufighters out of an assortment of dirt strip airfields in the same area and gifted me his Webley revolver and a few other weapons he flew with after being shot down once.

So a web search turned up this (among other less dramatic photos that didn't show the conditions the Aussies were fighting in):

[IMG][/IMG]

That is a No.4 rifle, not a SMLE. Our Aussie members probably already know there was some issue of No. 4 rifles during WWII, but I wasn't aware of it.

I'm not an arms historian; about all I was aware of was that Aussies did make use of the No. 4 rifles during the later Korean War, including during Kapyong, where they fought on a neighboring hillside beside the Canadian PPCLI, stopping the assaulting ChiComs and allowing retreating American forces to escape encirclement.

So, then I went looking for the online Aussie WWII pams. And way in the back of Small Arms Training, Volume I, Pamphlet No. 3 - Rifle, 1943, Australia is APPENDIX III RIFLE No. 4 Mk. I. and I.*





So perhaps in writing the Canadian 1945 Shoot To Live, the author cribbed what he gave as his zeroing information from what the Aussies had written two years earlier for the No. 4 rifle.

And then Lt. Col. Johnston decided the Aussies were also wrong with their wartime version of sighting the No. 4 rifle 8" high at 100 yards with the 300 yard sight setting - and added an additional half inch to make it +8.5" in the zeroing instructions he provided?

[Surpmil]

Right back at you:

Why in your opinion does that variation at 100 yards in the Canadian 1945 Shoot To Live become an explanation for DELIBERATELY sighting in with a 2.5 MOA error at 100 yards - an error that then increases the error of the POI versus POI as the ranges increase after that?

As per my earlier posts, when you have an accepted and stated variation of 2 MOA, an "error" of 0.5 MOA does not appear to be significant, not to me anyway.

An error, BTW, that wasn't used in sighting in by Canadians BEFORE the 1945 pam was published, if that 2 MOA variation is the explanation.

Do you mean an earlier Canadian manual specified the 6.5" POA above POI as per the UK manual, or is that an assumption that the Canadian Army used the 6.5" POA before STL was published?

And also BTW, an error that the Brits chose not to change their zeroing procedures to emulate the Canadian pam after it was introduced?

So we have confirmed from actual range experience that the 6.5" is correct, or at least more correct on average, than the 8.5" option?

One thing is clear I guess: the Australian manual did not adopt the 8" figure from STL, so either it was independently arrived at, copied from an earlier Canadian(?) manual, or the UK manual(s) were erroneous.

Unless actual range testing has proved otherwise?