Cover your eyes — he’s gonna open it!

[P0H0]

I stand corrected — I just got home and looked at the box. It’s actually 174 grain FMJ. So its what Alan really likes - close to the MkVII.

A picture of the box is HERE

[ssgross]

You were fortunate. Yours appears to have been in temp-controlled storage. Some of the grease on mine, and wax wrap around the wood, had clearly been subjected to higher temps, melting and staining some of the wood. My wood didn't come out as bright as yours, some areas no matter what I did still were dingy. Still pretty nice and clean - clean enough that when I fitted a NOS long butt, it matched just like it had been there in storage on the rifle for 75 years.

[Alan de Enfield]

I stand corrected — I just got home and looked at the box. It’s actually 174 grain FMJ. So its what Alan really likes - close to the MkVII.

A picture of the box is HERE

It is boat-tailed so if your throat is worn then it will not be accurate as 'years of cordite use' wears the barrel in a very different way to NC powders.

More information :

Use of Cordite in Rifles

'Regulations For Army Ordnance Services', Vol.3, Pam.11A (1949) comments:-

APPENDIX 15

(referred to in para.29)

USE OF .303-IN CORDITE AND N.C. AMMUNITION

1. The action of Cordite propellant in the barrel of a .303-in. weapon is quite different from that of N.C. propellant.
Cordite gives a rapid build-up of pressure with great heat, leading to pitting and erosion of the chamber end of the barrel.
N.C., however, gives a more gradual build-up of pressure with less heat, and this in turn gives uniformity of barrel wear from chamber to muzzle, the amount of pitting and erosion being greatly reduced.

2. With Cordite propellant, set-up of the bullet is most pronounced and even when the chamber end of the barrel is well worn, the muzzle end still has sufficient rifling left to impart the necessary spin. As the wear advances up the barrel, so the accuracy of the weapon is progressively reduced.
With an N.C. propellant, set-up of the bullet is slow and by no means so pronounced, due to the more gradual building up of pressure. The barrel retains its original accuracy until wear reaches a critical stage, when a sudden falling off in accuracy occurs.

3. It can be seen by comparison with the effects of barrel wear that to use N.C. ammunition in a barrel which has fired Cordite will give serious inaccuracy in flight, whereas the use of Cordite ammunition in a barrel which has fired N.C. gives good accuracy, but serious changed the wear pattern of the barrel.
In the first case, i.e. a weapon which has fired Cordite ammunition the barrel will be eroded and fissured in the first few inches up from the chamber, the part in which obturation should occur. The poor set-up of the bullet, in the N.C. cartridge is not sufficient to give good gas sealing in such a barrel and the bullet does not, therefore, receive the maximum impulse. The resultant loss in velocity and instability due to lack of spin lead to a high degree of inaccuracy.
In the second case, Cordite ammunition fired from a barrel which shows uniformity of wear from firing N.C. ammunition, has an adequate reserve of set-up that ensures full gas sealing, with satisfactory velocity and spin. Unless the barrel wear is in a advanced stage due to firing a large number of N.C. rounds, there will be no immediate appreciable loss in accuracy. Furthermore, the decline in accuracy for Cordite ammunition will follow the normal gradual fall-off experience in weapons firing Cordite alone, as the wear at C of R progresses.

4. Trials have proved that even if only a few rounds of Cordite ammunition are fired from an "N.C." barrel, the ensuing accuracy life when N.C. is subsequently fired is reduced considerably. The occasional and restricted use of N.C. in a "Cordite" barrel will however, have little effect on its ensuing accuracy life for Cordite, although naturally the fire of N.C. will not be very accurate.

5. The effect of wear of barrels can be determined by firing shots through a paper screen at 100 yards. If, on examination of the screen, all shot holes are not perfectly round, then the barrel is no longer fit for use.
The danger lies in the fact that bullets fired erratically from badly worn barrels may overcome their instability in flight and take up a steady flight in the direction in which they happen to be pointing, with short-ranging and disastrous results if used for overhead fire. Except under these conditions of long-range firing there is no risk involved, though in normal range firing inaccurate fire will result.

6. The following instructions regarding the use of .303-in ammunition have been issued to users and are governed by stocks and types of ammunition and weapons in current use:-

(a) .303 in. Vickers M.G.s in M.G. Bns.

(i)Mk.8z only will be used for overhead firing.
(ii) Mixed belts, i.e. Ball, Tracer, A.P., etc., will NOT be used.
(iii) Any barrel which has fired Cordite ammunition will NOT be used for N.C.; barrels will be stamped “7” on the trunnion block and returned to R.A.O.C. through normal channels.
(iv) Barrel life for N.C. will be assessed by unit armourers using the appropriate gauges.

(b) .303 in. Vickers M.G.s in A.F.V.s.

Here the overhead fire problem is not considered; the range is usually less than is the case with ground M.G.s. tracer ammunition is required as an aid to fire control, and prolonged fire programmes are not envisaged. Special mixed belts of Mk.8z and Tracer are provided in boxes clearly marked “For use in A.F.V.s only”. The reduced life of the barrels is accepted.

(c) Light M.G.s.

Cordite ammunition normally will be used. N.C. ammunition, however, gives a relatively small flash at night and if the Bren is being used for a special purpose, e.g., on a patrol, its use is permitted.

(d) Rifles.

N.C. ammunition will not be used in rifles except in such circumstances as quoted in para. “(c)”
above, if necessity should arise.

7. Belt packed S.A.A. for M.G.s is packed in boxes which are clearly marked with labels or stenciling indicating its proper use. It will never be de-belted and used for practice purposes in L.M.G.s or rifles.

8. It must be noted that the above restrictions apply only to ammunition fired from British weapons. All American ammunition is N.C. loaded and their weapons are designed to fire it satisfactorily.

[P0H0]

Should be okay with the barrel - it’s NOS/unissued.

That is awesome information on the effects accuracy due to corrosive ammunition. If I understand correctly:

1. Never fire a corrosive cartridge in a barrel that typically uses non-corrosive ammo. It will shorten the life and accuracy of the barrel. Just a few rounds will be enough to shorten the service life — cordite kills barrels.

2. You can fire non-corrosive ammo in a barrel that typically uses corrosive ammo. However the non-corrosive cartridge won’t seal as well against the chamber leading to a reduction in velocity and stability and thus accuracy. But, on the good side the non-corrosive ammo won’t shorten the barrel life (I think the corrosive ammo has that covered already).

Was early US 30-06 ammo corrosive?

My poor poor Mosin and K98 — no sense in feeding them the good stuff then! Just clean after each range day.

[P0H0]

You were fortunate. Yours appears to have been in temp-controlled storage. Some of the grease on mine, and wax wrap around the wood, had clearly been subjected to higher temps, melting and staining some of the wood. My wood didn't come out as bright as yours, some areas no matter what I did still were dingy. Still pretty nice and clean - clean enough that when I fitted a NOS long butt, it matched just like it had been there in storage on the rifle for 75 years.

Glad you were able to find a NOS stock — I am definitely relieved I unwrapped mine now and it turned out good.

[Alan de Enfield]

Was early US 30-06 ammo corrosive?

All ammunition is corrosive to some degree - some more than others.
The differences in the extract I posted is as much about ERROSIVE effects (not just CORROSIVE) of almost instantaneous high pressures and temperatures in the leade and first 'inches' of the rifling as the bullet is upset.
With NC the bullet is not subject to enough pressure to upset in the worn leade.

[GeeRam]

According to a couple dealers...here's the info. Boat tails...if this is what he has.

Interesting the seller says its 180gr and shows a photo of a box that is marked 150gr

[CoatiMundi]

Glad you decided to unwrap and use it. I had one a long time ago and sold it like a dummy. It shot very, well like a new gun I have replaced it with a late 1955 mk2 in .308.

[Brian Dick]

I think the OP was confusing "N.C." as "non-corrossive" instead of nitro cellulose. It's the erosion in the leade or throat of the barrel from cordite that causes instability of boat tail projectiles. It's unfortunate that no manufacturer makes ammo loaded with a flat base 174 grain Mk.7 projectile. The 174 grain boat tails are Mk.8 specification. It's what's available because the factories in Yugoslavia, (now Serbia/PPU), and Czechoslavakia, (now Czech Republic/S&B), were set up to produce MG ammo when they were doing it for military use.

[GeeRam]

It's unfortunate that no manufacturer makes ammo loaded with a flat base 174 grain Mk.7 projectile. The 174 grain boat tails are Mk.8 specification. It's what's available because the factories in Yugoslavia, (now Serbia/PPU), and Czechoslavakia, (now Czech Republic/S&B), were set up to produce MG ammo when they were doing it for military use.

Indeed.

The UK MOD had to get the Greek's to make the last batch they needed for the Cadet's back in the early 80's as Radway Green last made 303 in 1973, and all the machine tools were gone.

Kynoch still make 303, but only the 215gn Mk.V1 round in small quantities, so its a shame they don't offer Mk.VII rounds as well, as they would be easily sell all they could make, but I guess they are just not into making volume anymore.