Powder Ignition Failure

[Bruce_in_Oz]

One thing to note is that the old Lebel case is quite "fat".

Thus, any "lightish" load will settle below the centre-line of the case and thus below the flash-hole alignment.

With some powders, this "primer flash-over" is a recipe for a spectacular detonation. With others, you may get a hang-fire, or at best, the primer will JUST drive the bullet into the throat where it will stick, and the powder will be partly "melted" into a blob.

The old "Lebel" round was derived from similar black-powder cartridges of the era; see also include the 8mm Guedes / Kropatschek.

In those, one could jam in a fair swag of the old charcoal and get reliable ignition.

The early French powders were probably developed for loading by "bulk", not weight., i.e., an early "Pyrodex".

In BOTH cases, one must ask one important question:

"Was the case "fully formed" before insertion of the propellant or, as was the case (so to speak) with Cordite, the bundles inserted into a parallel-sided case BEFORE final neck-forming?"

The Brits' answer to the French introduction, was good-old "Cordite". The original .303 ammo had a PELLET of BP inserted before final forming and this method continued with the "smokeless" ammunition. The VERY first "trials" cartridge cases did not even have a "properly" formed shoulder and neck, but a weird "collar" that was a straight lift from an experimental Swiss cartridge.

The original primers were also different to those used today in "commercial" ammo.

Note that The .303 originally used a BOXER primer. Boxer was British and his system worked.

HOWEVER, when smokeless became all the rage, there was a sudden change to a BIG, chlorate-rich primer having two TINY, offset flash-holes. This set-up provided TWO jets of ignition flame into the back of the Cordite column. The Chlorates, sulphur etc in these primers provided a "flash" of greater endurance, this being necessary to ignite the new propellant.

Note that several of the other military cartridges of the same era also used "LARGE" primers in the 0.250" size range. Primer technology and chemistry were comparatively new fields at the time. Nitro-Cellulose propellants were likewise new and were noted to be MUCH harder to get started than tried and true Black Powder.

Style-wise, the Americans had become keen on the British-developed "Boxer" system, mainly because of its ease of reloading, back in the 1870s. Interestingly, in the 1930s, they made up a special batch of .30-06 "match" ammo that used BERDAN primers, SPECIFICALLY because this system seemed to give more consistent combustion, and thus, better grouping, than the Boxer-primed equivalent.

As for "recipes"; the US Ordnance System was slow to adopt the lead-based primer. However, commercial suppliers quickly cottoned-on to the fact that lead-based primers were an absolute boon to their reloading customers. The lead-based primer was a German innovation from before WW1, and was described (in German), in various technical publications of the time. They had also done a substantial amount of research into the corrosion issue as well.

Despite all of this study, ALL military ammo, EVERYWHERE was also CORROSIVE until WW2. The kick along came from the US introduction of the .30 M1 Carbine, with its "non-user-serviceable" gas system. Pretty much ANY genuine military ammo loaded before about 1950 (apart from M-1 Carbine) WILL be made with corrosive (chlorate-rich) primers.

The 7.62 NATO was the FIRST post-WW2 cartridge SPECIFIED from day one, to be "non-corrosive". Most "Eastern-bloc" SERVICE ammo is STILL fitted with CORROSIVE, lead-based primers; they are designed to go BANG first time, EVERY time.

The French were loading spectacularly corrosive .30-06 ammo, with both brass and STEEL cases, well into the early 1960s.