I've heard various claims about the strength of Martini actions. Everything from "you'd better not overload it.....they're not as strong as an SMLE" to "Martinis will withstand 62,000 CUP, why you could chamber one for .375 H&H Flanged Magnum". The first claim was I believe a little conservative and the second preposterous.....correct me if I'm wrong there.
But a dealer of mine has acquired a 1890s Enfield Martini in .303 British that's got a nitro-proofed barrel and is in good condition. The modern factory loads & even the surplus ammo for .303 isn't that punishing.
Surely the Martini can handle this? Am I going to have to load down? I intend to play with blackpowder & cast bullets too but it could take the higher pressure modern loads couldn't it?

I can't say for sure, but I've got one too. It was made by W.R. Pape, and I don't know if it's the same sized action as the Enfield. The rifling is long gone, but it's a heirloom, not a shooter.

Anyhow, the original .303 British Mk. I Cordite of 1891 had a mean pressure of 17.5 tons per square inch. This is from "The Lee-Enfield Rifle" by Major E.G.B. Reynolds, page 30. The No. 4 Mk. I rifle of WW II was proofed to 18.5 tons. Now the last time I choreographed it, some 60 year old Mk. VII DI Z was faster than new Federal loads. So I doubt if the Federal ammo was loaded past 17.5 tons. I can't say the Enfield Martini is safe with new factory ammo, but I'd shoot it myself.

A couple of points. If that Enfield action is the one they used with the .577/.450, which has a base area 2.15X of the .303, then it's capable of holding considerable thrust on the breech block. Also, comparing the British tons per square inch to American p.s.i. pressure is likely a case of apples and oranges.

Bye
Jack

I shoot 46.0 grains of H414 with CCI Magnum primers with 180 grain round nose Speer bullets in my Martini Enfield, and see no signs of high pressure. This is a maximum load according to Speer, so start lower. I have seen no signs of headpace problems, and the rifle is as tight as any .303 I've ever seen. As for commercial loads, the Fedrals don't seem to be near as heavy in recoil, and this is where I get my cases. Hope this helps.

Lee L.

I believe the MkVII DI Z are machine gun rounds aren't they? This might acount for the higher MV.

I believe the MkVII DI Z are machine gun rounds aren't they? This might acount for the higher MV.

Only thing I remember is that the "Z" stands for U.S. made "stick" powder...some memory of them being perfered for over the heads of friendly troop applications by machine guns. Believe they are machine gun rounds...last bunch of "Z" marked ammo to pass through was beleted. Was pretty normal to buy them that way and un-belt them (cloth belts) to sell the tracer rounds seperately.

The Martini can probably handle more pressure than the .303Brit is loaded to produce...but (ain't there always a but or two) that's a pretty old action and barrel, the cases aren't really happy running at hotter pressures, and at best you'd be able to equal the .308's speeds.

Think the action would live happier with a round with less taper...strong action, but that tapered case does seem to set back against the breech with some authority.

The .308 is only around 100-200 Fps faster than the .303 according to Speer. I immagine the machinegun ammo will surpass the standard rifle loads, but never tried to check it out. I think that an improved version of the .303 could even be loaded to surpass the .308 with less backthrust on the bolt head than the original .303.

Lee L.

The DI Z load was standard issue in Canada. DI = Defense Industries of Canada. Z = N on it's side, for Nitro powder, if I remember correctly. The velocity I got was 2420 fps, pretty close to the specified 2440 fps for the Mk. VII load (174 grain bullet). That doesn't look like hot loaded machine gun ammo. Federal 150 grain bullets only made 2550 fps, quite a bit short of the advertised 2700 fps.

I heard that Canadian 9mm WW II ammo was loaded hot for Sten guns. Browning HPs and Lugers could handle it, but it was too much for some others pistols. This story has been floating around for years, but I haven't verified it.

They surplused off the DI Z Mk VIII at $2-$3 a box of 48 and I've still got a couple of boxes left. Those were the days :cool:

Later: C = Cordite. Z = N = IMR type tube Nitro powder. A friend has a 3 volume book set on every Commonwealth .303 load. No Cordite was loaded in Canada during WW II, IIRC. A surplus powder, CR 17, was available when I started reloading in the late `60s, although it was getting scare by then. We were told it was .303 powder and to use 3031 data. It worked.

Bye
Jack

Jack:

As far as I could tell, the Canadian 9mm ammo had rock hard primers and current NATO ballistics...admit, those are warmer than the factory loads offered (closer to +P loadings). Chronograph of the time was one of the conductive screeen, move the knob until lights lit up, write the numbers by the lights down, add them up, and look in a conversion chart for the corrosponding vel...real pain in the butt, so never graphed that many rounds. Call it 124gr. at 1170fps from a Browning HP...and to get it to fire reliably, had to turn out an non-inertia full length pin. Staked in primers (remember tham as a tri-stake job, each stake kind of a triangle shape).

A couple of late WWII issue Iron bulleted/steel cased German stuff made it through the screens (only a couple fired out of many tries)...bullet was only about 100gr. and the velcity was an decent 1330fps.

Later (1950's )issue Cech. steel cored 9mm (bulit like the chi-com block rifle bullets...steel jacket, thin envelope of lead, steel core) was also hard primed, light (near 113 gr.), and fast (1285fps)..made "dimples" in sheet steel where normal FMJ ammo just made dents, but not real impressive penetration.
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If we can stand the digression,
I kept a couple of rounds...will go find them for the headstamps.
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The Canadian was marked: D 43 9mm and did have that tri-stake job. Brass case, jacketed bullet.

Guss I didn't keep any of the Cech. or Steel cased German rounds...may be in another place I've not looked yet, but suspect years ago I pulled them to get the bullets for some odd experiment or the other.

Did run across a couple of other rounds.

GFL 9M38 1949 This is brass cased and a silver colred bullet..but not magnetic, so I take the coloration to be some plated material. Memory tells me this was "real" sub-gun ammo and that although I only had a small amount, stopped shooting it in the Browning.

GE 11 16 D This is brass cased, magnetic bullet (which i take to be lead with a steel jacket) and I assume to be made in November of 1916.