Canadian 105mm TK C4 brass casing questions

[917601]

I have this Canadian 105mm brass casing, head stampings " 105mm TK C4", the ink markings are not readable. My question, the mouth is larger than the normal 105G steel case, 4 1/4 inch, and the primer tube is very long- up to the last 5 inches of the case mouth),would I be correct, semi correct, or way off base if I was to stick a M724 APDS projectile (blue projo marked M737) to fill it? I am striving to keep my collection accurate, is this case the Canadian equivalent to the US M115 casing? All replies and comments to steer me correctly greatly appreciated....I posted one of Hazord's old posts pictures of the M724/ M737 complete round. Thanks Hazord, your post on this some time ago is well appreciated.

 

[TimG]

The longer primer is indicative of it being used with WM Cordite or similar. Which, in comparison to the other Cordites is harder to ignite. WM Cordites are normally utilised when it is desired that the projectile should have a higher velocity than the normal loads. APDS, thus would be such a projectile.

I've been told that if the crew of a Centurion tank didn't know that an APDS round was being loaded, they certainly knew after it was fired.

TimG

 

[TimG]

Please ignore my post above as it is incorrect.

Although the Canadian 17Pr APDS used a long primer/igniter combination the use of a long primer for higher velocities doesn't necessarily hold true.

It appears the 20Pr used a No. 37 primer (15") across the board.

WM Cordite is not difficult to ignite. It is NH and FNH that are rated as fairly difficult and difficult to ignite. It is interesting to note that 'smoke' properties listed for FNH is "Considerable, but partly due to more powder (GP) for ignition."

A 1961 publication shows the 105 mm using a L1 primer (14.9") used with APDS, HESH & Paper shot. Also, a L2A2 primer (5.42") but no nature of rounds given.

Apologies for the previous misinformation.

TimG

 

[HAZORD]

Of course, a long primer would ignite a taller column of powder faster, but the length is governed by how much of the projectile protrudes into the case. The APFSDS and HEAT projos extend into the case more than any others.

One note on the M115 primer. It has a plug in the top end.

 

[917601]

Of course, a long primer would ignite a taller column of powder faster, but the length is governed by how much of the projectile protrudes into the case. The APFSDS and HEAT projos extend into the case more than any others.

One note on the M115 primer. It has a plug in the top end.

You may have answered my question, my case does have a slotted plug in the top of the primer tube. See picture. As the ink markings that would indicate the type of projectile loaded is worn off, ( I can make out an inked T"). I am becoming reasonably sure this Canadian case was loaded with the M737 projectile (or Canadian equivalent) primarily as the case mouth inside diameter is right at 4 1/4 inches. I am hoping the ink marking on the side of the case could confirm the load type ? "CA-99F13-02".

 

[917601]

Well, I had to give the case head marking another detailed look. A swipe with oil, a stirong light and the ink mark remains can be read - " TP/FSDS-T". The primer reads " C16 CA-99CC14/01" and measures 18 1/2 inches long, what exactly does that translate to?
if the FS means " fin stabilized discarding sabot", it appears the long primer tube would not accommodate such a finned projectile. Lost, no ideas.

 

[ammocat]

Way old thread but here it goes.

The C4 Cartridge Case with the C16 Electric Primer was used with the 105mm C-71 TP/FSDS-T projectile. Typically when TP/FSDS is seen the assumption is that it is some sort of practice long rod penetrator but in the C71 this is not the case. The projectile is 233mm long with a tubular sub-projectile. The tubular sub-projectile is 210mm long with an outer diameter of 55mm and a central perforation 25mm in diameter. The sub-projectile has three external spin damping fins to cause aerodynamic drag during flight and these cause the projectile to become unstable and tumble at a certain distance. This reduced distance permits training in smaller templates.

Photo is the sub-projectile.

 

[belcherbits]

Have you guys had any luck disassembling one of these APDS projectiles? It looks like it should unscrew, but I can't get it to budge (not even sure if it is CW or CCW) and I don't want to damage mine by using my traditional 'hammer and cold chisel' approach.

 

[HAZORD]

Post photos of the projectile.

 

[belcherbits]

APDS projectiles

Post photos of the projectile.

Sorry about the orientation; can't figure out how to turn it. The 20 pdr is on the left, 105 on the right. I can't use heat because of the plastic bands and I don't really want to disturb the paint. I have a partial 20 pdr as well and it definitely appears to be threaded. Any thoughts?

 

[HAZORD]

OK, the upper part of the TPDS (the body and the petals on top) is a solid piece of metal, aluminum or magnesium. When the projectile is fired, the centrifugal rotational forces cause the petals to break off, and the air catches the pot slowing it while the sub projectile continues downrange. Underneath, the base of the projectile is an aluminum cylinder that screws into the main body. It holds the sub-projectile in a cup shaped bore and pushes the ogive of the sub projectile into a taper machined into the petals at the top. It also holds the tracer element in the middle. The aluminum base is usually screwed into the body and has adhesive on the threads. Sometimes the base will unscrew on the fired projectiles, but you would probably not be able to unscrew it without damaging the outside.

You might try putting the base end in some boiling water to see if it will loosen the adhesive so the base will unscrew.

I'm going to need to check one to see if the threads are left or right handed.