.303 Mk.VIIz ammunition

[vintage hunter]

I don't remember whereit was or exactly what it was about but i read an article a while back that made brief mention of .303 Mk.VIIz ammunition intended for use in Vickers machine guns and the fact that some British snipers favored it because of the improved down range ballistics over ''standard'' mk.VII rounds. Anyone have any additional info on this?

Information

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[TonyE]

A degree or two of confusion here.

Mark VIIz is simply a Mark VII round loaded with nitro-cellulose propellant instead of cordite (the "z" sufix indicates NC on all British ammunition). Introduced in 1917 using American DuPont No.16, Mark VIIz was made intermitently right through the life of the .303, the last being made by ROF Radway Green in 1973.

Mark VIIIz was introduced for Vickers guns in 1938 to give better ballistics for long range barrage fire. It has a 175 grain boat-tailed bullet and is loaded to slightly higher velocity (2.550 fps nstead of 2,450) and pressure (20-21 tons instead of 19.5) than the Mark VII. Due to the different erosion properties the two should not be mixed in machine guns, but it is not a concern in rifles. It also has a more pointed profile than Mark VII. The official line was that Mark VIIIz could be used in rifles in an emergency or when a lower flash was desirable, e.g. night patrols.

Some snipers may have preferred it, but it was not regular issue for snipers.

Regards
TonyE

[vintage hunter]

That sheds a little more light on the subject. Thanks. I do seem to recall the article stating the snipers resorting to the beg, borrow or steal scheme of things to obtain a supply of it. I've never seen any, wonder if there's still some flaoting around out there anywhere?

[Amatikulu]

Oh its still out there. I have several .30 cal cans with about 250 rounds in each can. But I burn through my ammo in chronological order and am stuck on a batch of 1938 GB Mark VII right now

[spinecracker]

I have access to about 1000 rounds of Kynoch .303 Mk.VIIz, and I have shot more than my fair share of it in the past. I have not found any significant differences between Mk.VII and Mk.VIIz out to 300 yards (then again, I am an awful shot....), and the Mk.VIIz I have shot has performed very well.