British Ordnance Collectors Network
Join over 14,000 collectors of inert military ordnance. Get expert identification help for shells, fuzes, grenades, and more — plus access our classifieds marketplace and decades of archived knowledge. Free to register, takes seconds.
British 120mm APFSDS service projectile.
- Thread starter SG500
- Start date
quoting from the original document here as i had no idea what it was either " The
side of the Core is buttress threaded, this connects with the thread inside the Sabot
which prevents movement of the Core within the assembled Shot and, on firing,
imparts drive to the Core."
Hope this helps as nothing else is mentioned about the Buttress Threading
side of the Core is buttress threaded, this connects with the thread inside the Sabot
which prevents movement of the Core within the assembled Shot and, on firing,
imparts drive to the Core."
Hope this helps as nothing else is mentioned about the Buttress Threading
Dave,
Buttress threads are a standard design thread that you could find defined exactly in a "Machinery's Handbook" which is used by machiists. Standard threads are V shaped. Buttress threads have one side perpendicular to the axis of the threaded item, and one side angled to the axis of the dart. Buttress threads are shown:
[ame="http://en.wikipedia.org/wiki/Buttress_thread"]Buttress thread - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Buttress_thread_form.png" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Buttress_thread_form.png/200px-Buttress_thread_form.png"@@AMEPARAM@@commons/thumb/6/6a/Buttress_thread_form.png/200px-Buttress_thread_form.png[/ame]
In the case of darts and sabots, the flat side of the thread is the closest to the tip of the dart, so that it can push the dart forward. Once the assembly leaves the barrel, the angled part of the thread helps the sabot pieces break away from the dart.
Hope this helps. Let me know if you have more questions.
John
Buttress threads are a standard design thread that you could find defined exactly in a "Machinery's Handbook" which is used by machiists. Standard threads are V shaped. Buttress threads have one side perpendicular to the axis of the threaded item, and one side angled to the axis of the dart. Buttress threads are shown:
[ame="http://en.wikipedia.org/wiki/Buttress_thread"]Buttress thread - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Buttress_thread_form.png" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Buttress_thread_form.png/200px-Buttress_thread_form.png"@@AMEPARAM@@commons/thumb/6/6a/Buttress_thread_form.png/200px-Buttress_thread_form.png[/ame]
In the case of darts and sabots, the flat side of the thread is the closest to the tip of the dart, so that it can push the dart forward. Once the assembly leaves the barrel, the angled part of the thread helps the sabot pieces break away from the dart.
Hope this helps. Let me know if you have more questions.
John
A
aaaaa
Guest
L23
L23A1 and L26A1
L27A1
L28A1
is L28A1 ever used ? or it's some sort of "rename" for L27 ?
Here's a picture of a sectioned 120mm to show the combustible cap that covers the fins.
Dave.
L28A1
is L28A1 ever used ? or it's some sort of "rename" for L27 ?
Don't know the answer to that one but I'm fairly sure that picture was one I took at Bovington tank museum a few years ago. May be worth asking them.
Dave.
Do you know who RLB stands for?
Joe
Joe
Try this - http://www.bocn.co.uk/vbforum/threads/3718-What-means-R-L-B
Basically it is the designation used by the Royal Ordnance Factory Birtley (factory since closed and moved to new facility down the road at Washington both near Newastle).
The factory had a brass foundry to manufacture ingots which were then turned into blanks for the production of large calibre (76mm, 105mm & 4.5" cartridge cases. It also produced the empty shells for armoured car, tank, naval and artillery systems. These were then forwarded to the filling factories (either Glascoed and Chorley [since closed] ) for completion. The foundry was later closed and the blanks were bought in instead.
Not sure what the name is being used for the factory these days since RO was bought by BAE SYSTEMS and underwent many changes of organisation name. Last I heard a majority stake in what was left of the BAE SYSTEMS organisation (both ammunition and vehicles) has been sold to Rheimetal.
The other items made were APDS and FSAPDS rounds for UK 105mm and 120mm tank systems. Note - the BY stencilled on the body of the L28A1 also refers to Birtley.
A
aaaaa
Guest
pic from Ian Wilcox FB page
This may help clarify the situation. Extract from a old Janes article on BAE Systems 120mm Tank Ammunition.
"XL23E2 APFSDS Projectile
In November 2006 the UK Ministry of Defence (UK MoD) announced that it was considering a programme to develop a 4th Generation tungsten projectile under the designation L28A2. The contract would be issued to BAE Systems, Global Combat Systems Munitions and would cover fabrication and test of prototypes up to, but not including, the design chill and qualification phase. They explicitly noted that this was not envisioned as a replacement for the DU-based L27 series ammunition used in the Challenger 2. The designation was therefore changed to L23A2 as it is seen more as a replacement for the first generation APFSDS L23A1 shot. British-funded firing trials to demonstrate terminal ballistics have been carried out. British qualification had been scheduled for 2009, but was held back to 2010, after which production for Oman began. The projectile will be backwards-compatible with the older L11A5 gun found in Jordanian Challenger 1s.
The XL23E2 shot is to replace aging Omani stocks of L23A1s, and may also be procured by the British Army for use in lower-threat environments that do not require the capabilities of the L27A1 DU projectile. This takes advantage of some work done on the L28A1 developmental projectile but features the lighter projectile weight (7.95 kg) of the L23A1 and integrates with the C3TR L18A1 propelling charge. The use of the C3TR propellant extends barrel life but reduces muzzle velocity. Due to improved penetrator design, external and terminal ballistics are still better than the L23A1, but decisions are still pending on final design and production. "
Hope this helps.
"XL23E2 APFSDS Projectile
In November 2006 the UK Ministry of Defence (UK MoD) announced that it was considering a programme to develop a 4th Generation tungsten projectile under the designation L28A2. The contract would be issued to BAE Systems, Global Combat Systems Munitions and would cover fabrication and test of prototypes up to, but not including, the design chill and qualification phase. They explicitly noted that this was not envisioned as a replacement for the DU-based L27 series ammunition used in the Challenger 2. The designation was therefore changed to L23A2 as it is seen more as a replacement for the first generation APFSDS L23A1 shot. British-funded firing trials to demonstrate terminal ballistics have been carried out. British qualification had been scheduled for 2009, but was held back to 2010, after which production for Oman began. The projectile will be backwards-compatible with the older L11A5 gun found in Jordanian Challenger 1s.
The XL23E2 shot is to replace aging Omani stocks of L23A1s, and may also be procured by the British Army for use in lower-threat environments that do not require the capabilities of the L27A1 DU projectile. This takes advantage of some work done on the L28A1 developmental projectile but features the lighter projectile weight (7.95 kg) of the L23A1 and integrates with the C3TR L18A1 propelling charge. The use of the C3TR propellant extends barrel life but reduces muzzle velocity. Due to improved penetrator design, external and terminal ballistics are still better than the L23A1, but decisions are still pending on final design and production. "
Hope this helps.
A
aaaaa
Guest
thank you, interesting does it use L27 core dimensions or not