Is This Machine Gun or Rifle Ammo
- Thread starter gerard488
- Start date
- Location
- Western Manitoba
Just reading on Wikipedia - I think the Mk VIIz was the change from cordite to nitro-cellulose powder. As per their write-up, should assume those have corrosive primers. They do not mention a specific version "only for machine guns", but such a thing might have existed?? I might have misunderstood - I am assuming that these VIIz have the same 174 grain flat based bullets as the VII used - front third is lightweight stuff - wood, cellulose, aluminum - makes the bullets very "rear heavy" - so the bullets will tumble violently upon impact.
Google is your friend. The short answer is yes
In 1938 the Mark VIIIz "streamline ammunition" round was approved to obtain greater range from the Vickers machine gun.[21] The streamlined bullet was based on the 7.5×55mm Swiss GP11 projectiles and slightly longer and heavier than the Mk VII bullet at 175 gr (11.34 g), the primary difference was the addition of a boat-tail at the end of the bullet and using 37 to 41 gr (2.40 to 2.66 g) of nitrocellulose smokeless powder as propellant in the case of the Mk VIIIz, giving a muzzle velocity of 2,525 ft/s (770 m/s). As a result, the chamber pressure was higher, at 40,000 to 42,000 psi (275.8 to 289.6 MPa), depending upon loading, compared to the 39,000 psi (268.9 MPa) of the Mark VII(z) round.[22][23] The Mark VIIIz streamline ammunition had a maximum range of approximately 4,500 yd (4,115 m).[24] Mk VIIIz ammunition was described as being for "All suitably-sighted .303-inch small arms and machine guns" – rifles and Bren guns were proofed at 50,000 psi (344.7 MPa) – but caused significant bore erosion in weapons formerly using Mk VII ammunition, ascribed to the channelling effect of the boat-tail projectile. As a result, it was prohibited from general use with rifles and light machine guns except when low flash was important and in emergencies[25] As a consequence of the official prohibition, ordnance personnel reported that every man that could get his hands on Mk VIIIz ammunition promptly used it in his own rifle.[21]
In 1938 the Mark VIIIz "streamline ammunition" round was approved to obtain greater range from the Vickers machine gun.[21] The streamlined bullet was based on the 7.5×55mm Swiss GP11 projectiles and slightly longer and heavier than the Mk VII bullet at 175 gr (11.34 g), the primary difference was the addition of a boat-tail at the end of the bullet and using 37 to 41 gr (2.40 to 2.66 g) of nitrocellulose smokeless powder as propellant in the case of the Mk VIIIz, giving a muzzle velocity of 2,525 ft/s (770 m/s). As a result, the chamber pressure was higher, at 40,000 to 42,000 psi (275.8 to 289.6 MPa), depending upon loading, compared to the 39,000 psi (268.9 MPa) of the Mark VII(z) round.[22][23] The Mark VIIIz streamline ammunition had a maximum range of approximately 4,500 yd (4,115 m).[24] Mk VIIIz ammunition was described as being for "All suitably-sighted .303-inch small arms and machine guns" – rifles and Bren guns were proofed at 50,000 psi (344.7 MPa) – but caused significant bore erosion in weapons formerly using Mk VII ammunition, ascribed to the channelling effect of the boat-tail projectile. As a result, it was prohibited from general use with rifles and light machine guns except when low flash was important and in emergencies[25] As a consequence of the official prohibition, ordnance personnel reported that every man that could get his hands on Mk VIIIz ammunition promptly used it in his own rifle.[21]
That is Defence Industries (CIL Dominion) Mk. VIIZ ammunition. Non-corrosive, Boxer primed, nitrocellulose (not cordite). Considered to be some of the best .303 ball ever made. Brass is considered to be superior for reloading.
It is standard small arms ammunition.
It is standard small arms ammunition.
Lee Enfield
CGN Ultra frequent flyer
- Location
- Republic of Alberta
Dominion Industries Mk7z
Inspector General of Canada. The Label should be dated!
I recomend to treat all surplus .303 ammo as corrosive. Canadian boxer primed .303 is not corrosive, but Canadian berdan was into the 1950s.
Mk7 ball was/is the standard from approx 1913 to present for .303 British rifles.
Z designates nitro cellulose powder (like 4895 or 3031) rather than cordite.
Cordite is a highly Errosive propellent as it burns hotter than NC propellents.
As stated 174gr open base "flat base" bullet, with a filler at the tip to act as a weight regulator and known to produce tumbling.
Inspector General of Canada. The Label should be dated!
I recomend to treat all surplus .303 ammo as corrosive. Canadian boxer primed .303 is not corrosive, but Canadian berdan was into the 1950s.
Mk7 ball was/is the standard from approx 1913 to present for .303 British rifles.
Z designates nitro cellulose powder (like 4895 or 3031) rather than cordite.
Cordite is a highly Errosive propellent as it burns hotter than NC propellents.
As stated 174gr open base "flat base" bullet, with a filler at the tip to act as a weight regulator and known to produce tumbling.
Years ago a friend gave me a half dozen rounds of .303, I enjoyed punching holes in the cans in the back yard, well I enjoyed all but one of those rounds. It was far more powerful than the rest and I darn near had to pack a lunch to get back to my shooting position. WOW! That was some wild recoil. I was a young'un back then and not aware of the potential for different loadings. Never forgot that ....... and that was in 1973.
Lee Enfield
CGN Ultra frequent flyer
- Location
- Republic of Alberta
I wonder if that was a proof load.
I can send you a few if you want to test them ;-)
Just to confirm your memory of course.
Thank you but I'll take a pass on the offer. I can't even imagine what it would do to my arthritic shoulders. I fired a full house 45/70 a while back and I paid the price. This getting old sucks but I am told it is better than not getting old.
Bravo tiriaq. This is great stuff suitable for rifles. Fired many a box and still have a few in storage. 1943 ammo was top notch and
bore cleaning after was a breeze. Some of the 1944 stuff was a bit more yellowy and bore cleaning was harder. Should be fine for
your Bren too. The Mk VIIIZ I believe was intended for the Vickers but I don't believe any of us has tried that recently. John
bore cleaning after was a breeze. Some of the 1944 stuff was a bit more yellowy and bore cleaning was harder. Should be fine for
your Bren too. The Mk VIIIZ I believe was intended for the Vickers but I don't believe any of us has tried that recently. John
Could be. When I worked for Lever Arms, we used to regularly get pallets of different marks of 303 ball ammunition. I remember on shipment from 1965 that came in that was marked with large LIGHT BLUE squares and black caution printed on them.
I set them aside, so they wouldn't get upstairs, without Mr Lever's permission. Even left a big cardboard placard on the pallets, not to put in the store.
Well, one of the other folks working in the area, decided to ship them to some of the retailers that used Lever Arms for a supplier. When asked WHY DID YOU DO THAT??
The reply was "The sign only said not to send them upstairs"
That was when Mr Lever's words "Never leave anything to anyone's imagination. If there is any way to screw it up, anyone will." sunk in.
It was a very good thing that all of the recipients of that ammo didn't put it on their shelves or offer it for sale to their customers. All of them were PROOF ROUNDS.
Very likely wouldn't have blown an issue rifle up, but with bubba being so prolifically active in those times as well as being gifted with the "over creative bug" many of the receivers had been altered in a manner that may not have been safe.
All of that ammo got back to us over the next couple of weeks. It sat in the warehouse, stacked three pallets deep for at least two years, before it disappeared. I heard later that it was given to a bunch of Vickers/Bren Gun shooters to put on a shooting display with. That was never verified and honestly, I wasn't that concerned at the time.
I had seen the occasional 48 round box of proof ammo before and since. Those boxes were always marked as "cartridges PROOF" on a pink label.
I am under the impression that Mk.VIIz was more for aircraft machine guns and as close to being match grade ammunition as production ammunition can be. This comes from a former CF small arms life cycle manager with a very deep knowledge on the subject.
- Location
- Southern Vancouver Island
That's the way I found that ammo to be for me from my 1st LE. A No1 Mk III post war commercial sporter that would put that ammo into 2" at 100 yds when I did my bit using the issue iron sights fitted on 'er.
