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Clearing cartridge
- Thread starter MINENAZ16
- Start date
Correct, you fire the gun with a long rope from a distance. In German it's called a "Aushilfskartusche" and the base of the shellcase has a "A" stamped in.
Regards, DJH
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glevum
Well-Known Member
Because he is ordnance aproved he is not afraid to ask such question, he knows that no other ordnance aproved member will make remarks like You did.
There are countries where clearing rounds are not used and the projectile is removed mechanicaly with a special tool. Just as Minenaz 16 showed.
If You are a member here for more than a year You could have learned that ammunition is such a broad topic that no person alive can know everything.
If Your post was a joke You forgot to add a ton of smilies.
Bob
Andy Naude
Well-Known Member
I have seen a 40 mm Bofor in the Simons Town Naval Museum. It could very easily be mistaken for a blank, the construction looks similar.
I try to learn everyday. I'm not a gunner or a former military, and sometimes it's not easy to understand documentation in english as I'm french !
Regards
Andy Naude
Well-Known Member
40 mm Bofor Clearing Round
Please excuse the poor quality of the photo. This was taken at the Naval Museum in Simons Town, SA.
On the far left is a 40 mm Bofor Clearing Round
Please excuse the poor quality of the photo. This was taken at the Naval Museum in Simons Town, SA.
On the far left is a 40 mm Bofor Clearing Round
Think of a well known dutch saying:
'There are no stupid questions, only stupid awnsers'
All British gun and howitzer ammunition be it QF or BL has a certain amount of sheet lead foil or tinfoil included with the propellant, provided it is necessary.
Each projectile with a copper driving band, when fired, leaves a copper residue in the barrel. The foil in the next round fired forms an amalgam with the copper, which becomes brittle and is pushed out by the next round fired, which in turn, leaves its own residue, ad infinitum.
Projectiles which do not have a copper driving band e.g. APDS, APFSDS, Blank cartridges, do not have the foil added.
This has been so from way back, certainly before WWII and may be much earlier.
They are not common, I have only ever seen one box of 40mm, so I had one. Possibly I just was not called upon to inspect any.
Larger calibres have tools for removing stuck fast projectiles but this may not necessarily be so for smaller calibres e.g. 20mm.
Having said this, if the chips were down operationally and there was no way of removing said projectile from the bore by the slow method, you would use whatever was available to remove it.
When I started in the business 6pr, 17pr and 20pr were in vogue, so I have included some corroborative evidence from the period.
The foil is sometimes placed as sheets on top of the propellant, sometimes crumpled up, sometimes in a cup, other times inside the cartridge and other wrapped around the charge. Where it goes is generally dictated by the type of propellant, e.g. stick or granular.
In the case of these 17pr cartridges the clearing charge sheets are double the size of the other cartridge.
All the copper is not necessarily removed by the following shell, particularly under operational prolonged firing, so a clearing cartridge is used.
Another use in earlier times may have been to remove as much copper as possible before making gutta percha bore impressions in the artillery workshop.
Each projectile with a copper driving band, when fired, leaves a copper residue in the barrel. The foil in the next round fired forms an amalgam with the copper, which becomes brittle and is pushed out by the next round fired, which in turn, leaves its own residue, ad infinitum.
Projectiles which do not have a copper driving band e.g. APDS, APFSDS, Blank cartridges, do not have the foil added.
This has been so from way back, certainly before WWII and may be much earlier.
They are not common, I have only ever seen one box of 40mm, so I had one. Possibly I just was not called upon to inspect any.
Larger calibres have tools for removing stuck fast projectiles but this may not necessarily be so for smaller calibres e.g. 20mm.
Having said this, if the chips were down operationally and there was no way of removing said projectile from the bore by the slow method, you would use whatever was available to remove it.
When I started in the business 6pr, 17pr and 20pr were in vogue, so I have included some corroborative evidence from the period.
The foil is sometimes placed as sheets on top of the propellant, sometimes crumpled up, sometimes in a cup, other times inside the cartridge and other wrapped around the charge. Where it goes is generally dictated by the type of propellant, e.g. stick or granular.
In the case of these 17pr cartridges the clearing charge sheets are double the size of the other cartridge.
All the copper is not necessarily removed by the following shell, particularly under operational prolonged firing, so a clearing cartridge is used.
Another use in earlier times may have been to remove as much copper as possible before making gutta percha bore impressions in the artillery workshop.
Attachments
I've always wondered what the 'A' was on those short 75mm German WW1 cases, thanks for the confirmation.
D
I forgot to say that the de coppering paragraph was taken from The User Handbook of Anti Aircraft Ammunition, 1949 edition and the plates from an old service manual.
I will take a photo of the cartridge case and submit it.
I am glad I reviewed this. The spell checker changed de coppering to deciphering.
I will take a photo of the cartridge case and submit it.
I am glad I reviewed this. The spell checker changed de coppering to deciphering.
Here is the 40mm Clearing cartridge, which is what the box said.
The case is very thick at the top.
The markings are in different style to others I have seen on this site.
The later 40/70 Clearing cartridge is crimped like many Blank cases.
The groove was made for a table lamp over 50 years ago.
The case is very thick at the top.
The markings are in different style to others I have seen on this site.
The later 40/70 Clearing cartridge is crimped like many Blank cases.
The groove was made for a table lamp over 50 years ago.
Darkman
Well-Known Member
OK I've read all of these posts and I'm confused. Is a clearing round/cartridge for firing out stuck projectiles or for de-coppering the barrel? I'm not ex-military, let alone a gunner.
I can understand firing out a stuck shell that has lightly engaged the barrel rifling - when an unused round is extracted and the shell gets left behind from ramming, but what about a shell that has progressed along the barrel from a misfire (problem with the propelling charge) and is firmly stuck. Surely expulsion with a charge under these circumstances would be very dangerous? I noted mention of firing the gun remotely using a long rope, but what about potential damage to the gun/barrel putting it out of action?
Clearing rounds I have seen are reduced in length so as to fit behind the end of a projectile, so firing out a stuck projectile using a charge sounds feasible. But I'm not sure about clearing a firmly stuck shell. Are there different drill procedures when a charge is used and where a stuck shell is extracted using mechanical means? Don't think I'd be keen to remove a live HE shell using mechanical force. I've also looked at a few different gun drill manuals and they don't mention drill for stuck shells - only drill for misfires that relate to the gun failing to fire at all.
I understand that different countries and guns/ordnance may have different procedures, but could someone please provide more clarity around this in general terms for British/Commonwealth ordnance (particularly Bofors, one of my main interests).
Thanks, Graeme
I can understand firing out a stuck shell that has lightly engaged the barrel rifling - when an unused round is extracted and the shell gets left behind from ramming, but what about a shell that has progressed along the barrel from a misfire (problem with the propelling charge) and is firmly stuck. Surely expulsion with a charge under these circumstances would be very dangerous? I noted mention of firing the gun remotely using a long rope, but what about potential damage to the gun/barrel putting it out of action?
Clearing rounds I have seen are reduced in length so as to fit behind the end of a projectile, so firing out a stuck projectile using a charge sounds feasible. But I'm not sure about clearing a firmly stuck shell. Are there different drill procedures when a charge is used and where a stuck shell is extracted using mechanical means? Don't think I'd be keen to remove a live HE shell using mechanical force. I've also looked at a few different gun drill manuals and they don't mention drill for stuck shells - only drill for misfires that relate to the gun failing to fire at all.
I understand that different countries and guns/ordnance may have different procedures, but could someone please provide more clarity around this in general terms for British/Commonwealth ordnance (particularly Bofors, one of my main interests).
Thanks, Graeme
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