.303brit Mk8 ammo and Canadian sling ???
- Thread starter Timberlord
- Start date
MkVIII ammo was designed for the Vickers machinegun, nitro-cellulose powder loading topped with a 175 grain boat tailed bullet.
According to Labbett & Mead's ".303 Inch" ballistics for the MkVIII, it is listed as 20-21 tons/sq versus 19.5 for the MkVII with a muzzle velocity of over 2500fps as opposed to the 2440fps of the MkVII.
The MkVIII ammo certainly exceeds the presssure limits of a No1 rifle and will be real close to max pressure on a No4 action.
According to Labbett & Mead's ".303 Inch" ballistics for the MkVIII, it is listed as 20-21 tons/sq versus 19.5 for the MkVII with a muzzle velocity of over 2500fps as opposed to the 2440fps of the MkVII.
The MkVIII ammo certainly exceeds the presssure limits of a No1 rifle and will be real close to max pressure on a No4 action.
I have the booklet from the DCRA Canadian Marksman Autumn 1992. In it Notice To All Users Of .303 Rifles. And states ... #4 .303 rifles suffered a sheared locking lug. In addition, examination of the empty casings indicated an excessive amount of stretching and many cases of flatterned primers.
And ......the Mk 8 ammunition was manufactured specically for the Machine Guns and the chamber pressure approches twice that of a normal .303 round.
As I stated above I personally used and saw the results in a new 1950 LB with less than 100 rds put through it, by me.
In the early 1990's Mk 8 ammo was mistakenly produced by IVI!
And ......the Mk 8 ammunition was manufactured specically for the Machine Guns and the chamber pressure approches twice that of a normal .303 round.
As I stated above I personally used and saw the results in a new 1950 LB with less than 100 rds put through it, by me.
In the early 1990's Mk 8 ammo was mistakenly produced by IVI!
Last edited:
I recall the cadets shooting new IVI 303 ammo and noted that it had the boattail bullet in it. I was concerend that this might be high pressure ammo and filed a report.
I was later advised that IVI made a mistake on the bullet, but the pressure was ok. I still have some of it but have never bothered to pressure test it.
I do recall a failed rifle in one cadet shoot. That may be what motivated me to write the report.
I gues it would be easy to fire some IVI and some DA and compare the velocity. Same weight bullet.
I was later advised that IVI made a mistake on the bullet, but the pressure was ok. I still have some of it but have never bothered to pressure test it.
I do recall a failed rifle in one cadet shoot. That may be what motivated me to write the report.
I gues it would be easy to fire some IVI and some DA and compare the velocity. Same weight bullet.
George, your memory is failing you! From C-74-305-DCO/TA-000; "The Cartridge Calibre, 0.303-inch, Ball, Mk 8 Cdn or Mk 8Z Cdn is provided for use in Canadian Forces with the Rifle, No.4, .303"
Ammunition produced by IVI and now Winchester was produced for the cadets and now for the Canadian Rangers. It is widely known through the CF Ammunition world that the quality control exhibited by IVI was little better than a pathetic joke.
Shot at 2007-09-29
Ammunition produced by IVI and now Winchester was produced for the cadets and now for the Canadian Rangers. It is widely known through the CF Ammunition world that the quality control exhibited by IVI was little better than a pathetic joke.
Shot at 2007-09-29
Last edited:
stencollector
CGN Ultra frequent flyer
- Location
- shilo MB, the armpit of Canada
So whats the deal then...OK to shoot in Enfield or not? I just picked up a couple 250 round belts of 1960s produced 8z Kynoch I was adding to my ammo cache. I would hate to reduce the life of my LB sniper just to save a few bucks on bullets.
This following is a CF internal pub that I photocopied about 25 years ago, back when my career manager had sentenced me to 48 months in Dundurn Saskatchewan;
"Mark VIII Z
Official title- Cartridge, S.A. Ball, .303, Mark VIII Z.
This cartridge, the last of the .303 ball marks, was developed in the late 1930's and approved for service on 01 November 1938. The earliest headstamps noted so far have been K38 Mk VIIIZ and K1939 Mk VIIIZ. During World War 2 it was manufactured almost exclusively by United Kingdom plants, however one experimental batch by Defence Industried Ltd., Verdun, Quebec has been noted. In postwar years it has been produced by a number of other countries.
Intended for use only in heavy machine guns, its purpose was to provide greater long range accuracy and this was achieved by using a ballistically well-designed 175 grain boattail bullet of about 1.335" overall length. The standard British powder charge is about 36.5 grains of nitrocellulose Neonite propellant. Contrary to popular belief it is not a super-velocity cartridge and the official prohibition against its use in rifles and light automatic weapons stems only from the rapid barrel wear induced by the boattail projectile after the barrel has been used for Mark VII ammunition. The cartridge is loaded to approximately the same overall length as the normal Mark VII cartridge. The projectile comprises a gilding metal or gilding metal-coated steel jacket and a lead/antimony core without a ligthweight tip insert. The projectile is normally secured into the case neck by crimping or coning into a flat fronted cannelure. The standard of accuracy for the Mark VIIIZ demands a figure of merit of 8 inches at 600 yards. Like the Mark VII already discussed, the Mark VIIIZ may also be found with the Arabic 8z headstamp after 1945. Specifications for the MkVIIIz cartridge call for a mean velocity of 2,400 +/- 40 fps at a pressure of 19 tons, with no single round exceeding 20 tons. The pull required to withdraw the projectile from the case neck is 60 lbs."
Personally Rob, I remember reading that the (T) had an active service life of 3,500 rds after which time it was to be returned to the armourers for a re-build. The Mark VIIIz will be hard on your barrel. I've personally retired my (T) from competition, but I will bring it with me in December for the obligatory happysnaps.
"Mark VIII Z
Official title- Cartridge, S.A. Ball, .303, Mark VIII Z.
This cartridge, the last of the .303 ball marks, was developed in the late 1930's and approved for service on 01 November 1938. The earliest headstamps noted so far have been K38 Mk VIIIZ and K1939 Mk VIIIZ. During World War 2 it was manufactured almost exclusively by United Kingdom plants, however one experimental batch by Defence Industried Ltd., Verdun, Quebec has been noted. In postwar years it has been produced by a number of other countries.
Intended for use only in heavy machine guns, its purpose was to provide greater long range accuracy and this was achieved by using a ballistically well-designed 175 grain boattail bullet of about 1.335" overall length. The standard British powder charge is about 36.5 grains of nitrocellulose Neonite propellant. Contrary to popular belief it is not a super-velocity cartridge and the official prohibition against its use in rifles and light automatic weapons stems only from the rapid barrel wear induced by the boattail projectile after the barrel has been used for Mark VII ammunition. The cartridge is loaded to approximately the same overall length as the normal Mark VII cartridge. The projectile comprises a gilding metal or gilding metal-coated steel jacket and a lead/antimony core without a ligthweight tip insert. The projectile is normally secured into the case neck by crimping or coning into a flat fronted cannelure. The standard of accuracy for the Mark VIIIZ demands a figure of merit of 8 inches at 600 yards. Like the Mark VII already discussed, the Mark VIIIZ may also be found with the Arabic 8z headstamp after 1945. Specifications for the MkVIIIz cartridge call for a mean velocity of 2,400 +/- 40 fps at a pressure of 19 tons, with no single round exceeding 20 tons. The pull required to withdraw the projectile from the case neck is 60 lbs."
Personally Rob, I remember reading that the (T) had an active service life of 3,500 rds after which time it was to be returned to the armourers for a re-build. The Mark VIIIz will be hard on your barrel. I've personally retired my (T) from competition, but I will bring it with me in December for the obligatory happysnaps.
stencollector
CGN Ultra frequent flyer
- Location
- shilo MB, the armpit of Canada
Well thats that then....8Z will be relegated only to my iron sight Enfields.
Lawrence, I beleive the final result of the investigation was that the 1992 IVI .303 ammo was, or part of that year was, mistakenly made with the machine gun charge. I used to have some spent cartridges from this lot. You could see Through the primers, looked like a cross after used, with light shinning through 4 holes in these spent primer. Headspace was good. I don't have a copy of the report though.
The late 80's and early 90's were a bad time for quality control in IVI. Entire lots of 5.56mm (numbering in the 1-2 million rd range) were rejected because of numerous defects and dumped south of the 48th parallel. At one time it was part of the Ammo Tech 6A course to have a tour of IVI, but our people had so many questions critical of their operations that the invite was withdrawn, permanently!
If you remember in Chilliwack at the annual service rifle match, a collector in town used to have us bring out his Lewis Gun to shoot for honours on the LMG stage. I used IVI .303 for those stages. Before the match I had to recrimp every rd that we used in order to ensure that the bullet didn't separate from the cartridge case. The list of problems from lot to lot and caliber to caliber was extensive and unfortunately records have been disposed of 3 years after that lot (or batch) leaves service use. Maybe thats why Winchester now manufactures our .303 FMJ!!
If you remember in Chilliwack at the annual service rifle match, a collector in town used to have us bring out his Lewis Gun to shoot for honours on the LMG stage. I used IVI .303 for those stages. Before the match I had to recrimp every rd that we used in order to ensure that the bullet didn't separate from the cartridge case. The list of problems from lot to lot and caliber to caliber was extensive and unfortunately records have been disposed of 3 years after that lot (or batch) leaves service use. Maybe thats why Winchester now manufactures our .303 FMJ!!
- Location
- Tucson, Arizona
It's the bullet, not the powder charge that is the culprit. Boat tail bullets fired in barrels that have used cordite extensivly, will not be as accurate due to the throat erosion caused by cordite. You can change a machine gun barrel in a minute or two, so cordite throat erosion is not a factor .
Now saying that Mk8z exceeds the pressure limitations of a No4 is a bit silly, since the .308 has a higher chamber pressure, and I haven't heard of any No4's blowing up. The longer range of the Mk8 is due solely to the design of the bullet.
Now saying that Mk8z exceeds the pressure limitations of a No4 is a bit silly, since the .308 has a higher chamber pressure, and I haven't heard of any No4's blowing up. The longer range of the Mk8 is due solely to the design of the bullet.
So is there a consensus that Mk8 is safe for bolt rifles? Same pressures? Accuracy the only issue?
I had no idea that IVI ammo was that bad...here we were wishing we could get some...
stencollector
CGN Ultra frequent flyer
- Location
- shilo MB, the armpit of Canada
So is there a consensus that Mk8 is safe for bolt rifles? Same pressures? Accuracy the only issue?
I had no idea that IVI ammo was that bad...here we were wishing we could get some...
Picked this stuff up at the last Wpg gunshow. It was only $10 a box, and he only had 3 boxes. A collector just had to have one box, so I doubled my money on that box and now just have these two.
No 8Z designation anywhere, and to top it off, it's soft point. Headstamp is
IVI 303 BRIT
