Clearing cartridge

[flak18]

Method for clearing stuck projectiles in 105mm Howitzer in Australia...poor old gun sergeant had to go to the end of the barrel with a long rod. Attached to the end of same was a hollow bell shaped brass piece. Very gingerly the No 1 of the gun would feed the rod down the barrel and the brass piece would slide over the fuze. Then the projectile would be slowly encouraged down the barrel towards the breech....where a waiting gunner would remove it to a safe place. I saw this happen one time only. The shell was not really stuck and in fact had not even been fired, just loaded incorrectly and needed to be removed as the fire mission had been cancelled. In reality, I honestly do not think any gun safety manuals would permit firing another charge behind a stuck projectile. Clearing of debris only, surely.
My opinion only.

 

[glevum]

Sometimes time is of the essence in getting the gun firing again....

A clearing charge is a very quick way of clearing a projectile.

 

[Quatermass]

REMOVAL OF JAMMED SHELL FROM THE BORE OF THE GUN

A. When the projectile is in the loaded position, i.e. has not taken the rifling.
B. When the projectile has been forced to take the rifling by firing but not left the gun.
Proceed as following:-

A. The projectile will be ejected under the supervision of the Gun Position Offer by the ejector or by firing as found most convenient.
By ejector.- Place a quantity of sacking or similar material in the chamber to act as a cushion and prevent damage to projectile or breach mechanism and close the breach. Lay the gun in a safe direction at slight elevation and insert the ejector from the muzzle, taking care that the head fits snugly over the nose of the shell, clear of the fuze. The final adjustment of the ejector should be carried out by one person, all others being behind the muzzle. Ropes previously fitted to the stave of the ejector are taken down on each side of the gun and manned equally by the detachment. the stress is taken and the projectile forced to the rear. Should that fail, the ejector may be withdrawn about 1 -3 inches by one person, the ropes manned and a jerk given to the ropes, which will move the projectile in most instances.
By firing.Guns using fixed ammunition can be cleared by loading a cartridge in the normal manner laying the gun in a safe direction, and firing. In this case a shortened cartridge case must be used; the propellant charge and primer being taken from another cartridge.

B. This is very unlikely to happen, but if it should, the incident should be reported at once, in the case of shell containing explosive, to the R.O.A.C., for the attention of the Inspecting Ordnance Officer, who will make the necessary arrangements to clear the bore. In the case of solid shot or shell with inert filling, where there is no explosive risk, it will be reported to the E.M.E.
In case of extreme operational urgency, where technical supervision is not available, unit commanders may attempt removal of abnormal jammed shot or shell. If Mechanical ejection fails, the Gun Position Officer will clear the bore by firing. As there is a risk of a premature, the operation must be conducted under precautions as follows:-
Lay the gun at maximum elevation and in a safe direction, load a propellant charge (maximum charge to reduce as far as possible the risk of the round falling short) and arrange to fire by percussion, using a long lead (at least 15 yards). Place all personnel under cover and, when all is clear, fire from a covered position. The bore should be inspected, and if damaged, the gun will be placed out of action for technical examination.

HANDBOOK FOR THE ORDNANCE, Q.F., 40-MM., MARKS I,I* AND III 1941 AMENDENTS (No. 4)

 

[AMMOTECHXT]

From my course notes, taken in 1978: A clearing charge is used with QF Fixed calibres only. If when unloading an unfired round, the cartridge case separates from the projectile, leaving the projectile stuck at the commencement of rifling (C of R). A clearing charge is a shortened case containing 2/3 of the normal charge and is loaded to clear the projectile from the barrel. De-coppering, as AE501 has pointed out, was achieved by adding lead / tin foil to the normal propelling charges, especially those increments that were added to ensure longer range.

I just checked my course notes and the only equipment in British land service in 1978 that used a clearing charge was the 40 / 60 Bofors - one of the earlier posts in this thread shows its appearance as similar to a blank cartridge having a crimp. By then the 20 Pr clearing charge shown at the start of this post was already obsolete.

Just as an aside, in 1989 I was Range AT for a night firing of Milan anti-tank missiles in Northern England. The unit doing the firing also had other types of weapon, to make the training more realistic. These included .50 heavy machine guns. At one point the crew of one of the guns had to change a barrel but unfortunately did not secure the fresh barrel to the gun correctly. There was about 3/4 inch (about 20 mm) mismatch. On firing the first round with the fresh barrel there was an explosion and the crew was peppered with pieces of the cartridge case, one of the men was hit in an eye and had to be taken to hospital. The first I knew of it was when the unit's attached REME sergeant told me about it and showed me the cartridge case, about 3/4 inch was blown out from the side, where the bottom of the round had not chambered. He asked whether I might be able to remove the bullet from the barrel - it was lodged about a quarter of the way down the barrel from the breech end. I told him that I could think of a way but it might mean that the interior of the barrel could be damaged. He asked me to go ahead. Reasoning that weapon barrels are designed to withstand high pressure I inserted a single length of detonating cord into the barrel, going down at least half way and plugged around it at the muzzle end with mud. I attached a detonator well clear of the barrel, to avoid micro-cratering the interior of the barrel with metal from the detonator. When it blew, the bullet was blown out of the breech end of the barrel. A few weeks later the REME sergeant contacted me and told me that no damage had been caused to the barrel and after cleaning, it was as good as before. I believe that the crew member who had been injured suffered no lasting effects. This solution was an improvisation. I had never heard of it before. However, many years earlier I had seen an x-ray of the barrel of a sub-machine gun that had had weak charge 9 mm rounds fired in it. The x-ray showed about ten bullets neatly end to end, one after the other in the barrel, the foremost bullet being about 3/4 along the length of the barrel. That would probably be more difficult to remedy but it probably got me thinking.