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Direction of twist in Enfield barrels?

Posted: Sat Apr 01, 2006 1:18 pm
by Brian the Brit
At the range this afternoon and yes, I do know what date it is, someone told me that the direction of twist on Lithgow .303 rifles is opposite to that on rifles of UK manufacture "to take account of the effect of the rotation of the Earth in the southern hemisphere"

My immediate response was of course, "Bollocks!" but the chap (who is not a wind-up merchant) was most insistent that he has seen an article in a magazine to this effect and said he will bring me a copy to prove it.

While I know the Coriolis effect to be relevant to very long range artillery and missile ballistics, I don't see how it would be relevant at small arms ranges. Also, wouldn't it depend whether the projectile was being fired from North to South, vice-versa or parallel to the Equator?

If this were a relevant concern, wouldn't it have meant that all Australian made rifles would have had to be rebarrelled before use at Gallipoli and ditto all UK rifles prior to the Boer War?

So far as I am aware Australian and UK Enfields have the same direction of rifling twist. Bollocks, methinks. But am I right?

Brian :roll:

Well, he made you believe it....

Posted: Sat Apr 01, 2006 3:11 pm
by belgmart
Which is what the 1st of April is for! The Oz. Gallipoli rifles of course were FTR'd before being shipped out, and has to go through it again when going back... Makes me wonder how you Brits did things in the Falklands, with a rifling twist the wrong direction! :bigsmile:

Posted: Sat Apr 01, 2006 3:24 pm
by dromia
Enfield rifled 5 groove Left Hand Twist as per the sealed patterns methinks, if some one wants to trawl the LoC for an Aussie RH variant then good luck to them.

Mind you it is hghly conceivable (just like the Virgin M) that a few alcohlol crazed Aussie gunsmiths stuck the barrels on back to front hence the anomally to the sealed pattern your friend was on about.

No doubt Eoin will be able to verify this.

:bigsmile:

Posted: Sun Apr 02, 2006 7:12 am
by Ned
you couldn't put one in backwards unless it was made as a right hand twist barrell. I thought they all stuck to the plan of left hand twist. Most civilian barrels are right hand twist.

Here's one for ya Eoin, what was the twist, left or right in the SLR or L1A1 and wasther difference in the brit version to our aussie one, considering they where made to different blueprints?

How are ya anyway mate? Long time no talk eh? :bigsmile: :AUS:

Posted: Sun Apr 02, 2006 7:57 am
by dromia
"Shoot straight you bastartds"

Edward Woodward in Breaker Morant?

Where they shot them under rule 303.

Nice collection of Long Lees in that film.

Posted: Sun Apr 02, 2006 8:42 am
by Ned
Certainly is sir

What is the badge from you have at the end of your posts?

I loved the pics of woftam!!

I was talking with regulary before he went to Ireland. Time differences and his work made it hard to keep in contact.

Love his solar panel for a sex machine on his noggin !

Hope the bastard brought something back with Kilkenny draught in or on it !!

Cheers

NED

:AUS: :pirate:

Posted: Sun Apr 02, 2006 9:31 am
by dromia
It's the clan Sutherland, my clan and surname, badge and motto.

It was also the unit badge of the 2nd Battalion (Sutherland) of the Seaforths.

Motto "without fear".

Posted: Mon Apr 03, 2006 4:03 am
by Aughnanure
Australia did have some right hand twist barrels but the rifles didn't go through an FTR. It was done at unit Armourer level. The Armourer heated the barrel up to a dull red, having first removed the woodwork, and applied the 'Wrench, Barrel, twist reversal, Mk2**' This clamped to the muzzle and the Armourer applied force (torque) in the desired direction until the required twist was obtained. There were some variations due to the strength or lack thereof of some Armourers and twists of 9" and 11" are not unknown. There is a sure way to recognise these retwisted barrels and that is that there is often a slight reversal where the wrench was clamped to the barrel at the muzzle. These rifles usually show excessive wear or may have been counter bored to remove the problem. TRUE.

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First heard about the reason for LHTwist when I did my Basic Armourers' Course in 1955. It was in a short history of the Lee-Enfield that we were given and was supposed to have been excerped from the British Manual of Small Arms. The gist of it was that it was to counteract the drift of the bullet due to the rotation of the earth in the northern hemisphere.

Wheather this was when firing South or North wasn't mentioned. The effect of East versus West also went unanswered. I never asked the instructors as most of them had rather narrow Service minds and were likely to take hard questions as 'having a shot at them'.

Australian barrels were all LHT, however there just might be a few around that are RHT as a goodly number of civilian rifles were returned to service during WW2 and it is possible that some of these could have been fitted with trade barrels having a RHT. Skennerton probably has an answer.

The twist in the SLR, as I remember was RH. Can't say much about the British version as I only handled a few of them and never kept my personal Brit one for long as it went to a serious collector.

The British ones used to pop up in stuff coming back from Malaya and I guess an equal number of ours found their way to Britain. The military have a happy knack of requiring only the correct quantity of an item on occassions.

The walnut wood from them was much appreciated especially by Army marksmen who liked to have 'one up'.

Good to see you back, Ned. Don't forget to drop in on the Aussie site.

Eoin.

Twist

Posted: Mon Apr 03, 2006 8:04 pm
by JBS
Taking into account the earth's rotation for a rifle bullet would be so minute' that it would be impossible to do using rifle sights. Anyway the bullet does not stay in the air long enough to calculate it. Rotation in the Field Artillery is a different thing, altogether. Rotation correction is figured in as part of the equation of deflection. Still it is so minute' as to not make a large difference. It is only calculated in as being necessary to put the first round precisely on target, therefore achieving perfect accuracy. I used to do that for a living. Calculate Fire Direction Data for Field Artillery, that is.

Twist

Posted: Mon Apr 03, 2006 8:09 pm
by JBS
Oh, I almost forgot...I have a #4 MK1 that is 2 groove with a left hand twist.