VICKERS MK6B's resto

[tankbarrell]

Looks like a .303 blank to me, which is what the dischargers used originally.

[colin jones]

Adrian, you are spot on and thanks for the drawings. They were certainly easy to follow although I did make a few mods for the extractor area so it can in fact fire a blank to ignite a oxy/accet balloon or something similar.

[Bob Carriere]

...... here barbies are dolls and.....and a big bottle of tomato sauce.

What no wine! !!!!!!!

You are just as quick with the replies as you are at machining parts.....

Bob C.

[Bruce Parker (RIP)]

Originally Posted by tankbarrell

Looks like a .303 blank to me, which is what the dischargers used originally.

Not quite a blank. It was a ballistite round. Kind of like a blank. I'm actually surprised these square dischargers were used instead of cut down SMLE rifles.

[Lynn Eades]

Bruce , I think it is a blank. (in Colin's pictures) The Ballistite round is plain ended, with no crimp.
The Ballistite round is used to launch a grenade, so quite different with quite a big charge compared to the crimped blank.
To help stop breaking the stock the No1 rifles were wound with wire when used for grenade launching.

[David Dunlop]

Hi Lynn.

Not to deflect Colin’s Thread for too long, you are correct up until about 1944/45 .303 Grenade Launching Rounds.

Prior to that date, sorting out these rounds is a complete PITA, particularly if dealing with spent casings. Brass cases were standard Ball Cartridges with no special Head Stamps, or crimping. Some iterations had fully blackened, or partially blackened cases and were described in great detail in written documentation, but rarely, it seems, were the differences ever deemed important enough to make the rounds readily obvious to the end user in the field, or at sea. Most of the earlier cartridges were a slightly heavier load of standard powder with a small insert of guncotton fore and aft with a lacquered plug and no crimping. Ballistite and Cordite loads did not gain prominence until the 2nd War when Rifle Grenades, Anti-Tank Grenades and Smoke Grenade usage really evolved, along with Line Throwing equipment for the Navy. I think the Cordite loads were a tropical thing where they stood up better in high humidity to Ballistite.

By 1944/45, all Grenade Launching Rounds had been standardized in so far as head stamps and they all bore the letter H, with a following number (1-8 eventually), the rosette crimp was also standardized and the cases were either blackened any of the front third, the rear third, or two small black bands roughly amidships.

It’s amazing it took the bureaucrats 45 years to sort these rounds out properly. Makes one wonder how many poor sods grabbed a blank round by mistake at a critical moment and what the consequences of that mistake must have been.

David

[David Dunlop]

Colin.

I hope you are getting some nicer working weather now, though your daylight time might be shortening up a bit.

David

[colin jones]

Yes we are David, it's been in the 20s the last few days but we are heading for 40+/- next week. I can get quite a bit done when it's a nice day and not -40 or +40

[David Dunlop]

Curiosity question, Colin.

As you have been steadily bringing these two beauties back to life, and getting all their parts and kit reinstalled in them, when you are under the turret, or inside the hull now, do you find yourself having a much greater appreciation, of just how ‘up close and personal’ the tank environment actually was? Not a lot of wiggle room to go around and just how important team work would really have been for things to run smoothly? It can be a real eye opener on the life and times of our past generation and their war service.

David

[lynx42]

Originally Posted by David Dunlop

Hi Lynn.

Not to deflect Colin’s Thread for too long, you are correct up until about 1944/45 .303 Grenade Launching Rounds.

Prior to that date, sorting out these rounds is a complete PITA, particularly if dealing with spent casings. Brass cases were standard Ball Cartridges with no special Head Stamps, or crimping. Some iterations had fully blackened, or partially blackened cases and were described in great detail in written documentation, but rarely, it seems, were the differences ever deemed important enough to make the rounds readily obvious to the end user in the field, or at sea. Most of the earlier cartridges were a slightly heavier load of standard powder with a small insert of guncotton fore and aft with a lacquered plug and no crimping. Ballistite and Cordite loads did not gain prominence until the 2nd War when Rifle Grenades, Anti-Tank Grenades and Smoke Grenade usage really evolved, along with Line Throwing equipment for the Navy. I think the Cordite loads were a tropical thing where they stood up better in high humidity to Ballistite.

David

I just nicked out to our museum display and grabbed a couple of photos of the .303 "EY" Grenade launcher, grenade with base plate and the ballastites for your information.



IMG_6502.jpg

Open tin of Ballastites showing black to cases and that they are not crimped like a blank.

IMG_6501.JPG

M36 Mills Bomb fitted with the base plate ready to drop into the cup holder.

IMG_6498.jpg

An unopened tin of .303 ballastite rounds for the grenade launcher dated 22nd July 1941

IMG20190222202120.jpg

An "EY' SMLE. .303 rifle fitted with the launcher cup, a grenade with base plate and a box of ballastites. The copper banding on the rifle is both to protect the hand holding the rifle and to give the holder a good non slip place to grip it.

Regards Rick.

[Tony Smith]

Originally Posted by lynx42

An "EY' SMLE. .303 rifle fitted with the launcher cup, a grenade with base plate and a box of ballastites. The copper banding on the rifle is both to protect the hand holding the rifle and to give the holder a good non slip place to grip it.

Regards Rick.

Neither of those are the reason for the copper wire banding.

The Cup, Discharger is fitted to the nosecap of the No1 Mk3 Rifle, and is not supported by the barrel. On firing, the recoil of launching the grenade is transmitted through the Cup, to the Nosecap, and then to the timber stock. As Lynn has said, the wire prevents the timber from splitting from this recoil.

The No4 Mk1 Rifle was an improvement on this design, where the grenade launching spigot was fitted to the bayonet lug, which is part of the barrel. There is no need to wire wrap the No4 Rifle for grenade launching, as the stresses of firing are not transmitted through the timber stock, and there is no need to provide hand protection or grip.

It should also be noted that the No1 Mk3 SMLE has a thicker heavier barrel that the No4 Rifle, so if either barrel was liable to burst from excessive pressure, the No4 would go first.

[Tony Smith]

Blank rounds are ".303 Blank, L Mk I", and again I have several of these from '40, '41, and '43 manufacture. All are headstamped L and dated, and are not re-stamped Ball cases.

.303 Blank cases can be either long or short nosed and are ALWAYS crimped to differentiate them in the dark from Grenade rounds, which have no crimping. Oddly, this foolproof feature was not continued with 7.62mm Grenade rounds which are crimped exactly like Blank.

Colin, your Blank doesn't look like a military round. It's either a PPU commercial blank, or a reloaded and crimped "Highland" case?

[lynx42]

Originally Posted by Tony Smith

Neither of those are the reason for the copper wire banding.

The Cup, Discharger is fitted to the nosecap of the No1 Mk3 Rifle, and is not supported by the barrel. On firing, the recoil of launching the grenade is transmitted through the Cup, to the Nosecap, and then to the timber stock. As Lynn has said, the wire prevents the timber from splitting from this recoil.

Thank you Tony, You learn something every day on MLU. (I'll have to go and dig up the Digger who told me the, obviously incorrect, info. Unfortunately he passed away a few months ago. RIP. Harry. )

It is still nice to have a setup showing the "EY" to which I can now give the corrected information.

Regards Rick.

[Tony Smith]

Originally Posted by David Dunlop

Hi Lynn.

Not to deflect Colin’s Thread for too long, you are correct up until about 1944/45 .303 Grenade Launching Rounds.

Prior to that date, sorting out these rounds is a complete PITA, particularly if dealing with spent casings. Brass cases were standard Ball Cartridges with no special Head Stamps, or crimping. Some iterations had fully blackened, or partially blackened cases and were described in great detail in written documentation, but rarely, it seems, were the differences ever deemed important enough to make the rounds readily obvious to the end user in the field, or at sea. Most of the earlier cartridges were a slightly heavier load of standard powder with a small insert of guncotton fore and aft with a lacquered plug and no crimping. Ballistite and Cordite loads did not gain prominence until the 2nd War when Rifle Grenades, Anti-Tank Grenades and Smoke Grenade usage really evolved, along with Line Throwing equipment for the Navy. I think the Cordite loads were a tropical thing where they stood up better in high humidity to Ballistite.

David

I have a fair collection of .303 Blank and Ballistite, and it seems to contradict what you say.

Pictured below are British, Australian and NZ manufactured Ballistite grenade launching rounds. All are marked on the container and headstamped as H Mk1z. The British and Australin cases are half chemically blackened, while the NZ cases are half Violet resin.

The British rounds are dated Oct 1940.
The Aust rounds are dated Sep 41.
The New Zealand rounds are Apr 42.

The "z" in the name indicates that Ballistite is a Nitrocellulose powder, not Cordite. The Ballistite is not only more stable in tropical conditions, but also provides more energy than Cordite can provide in the case volume.

[Tony Smith]

Originally Posted by Tony Smith

Pictured below are .. Ballistite grenade launching rounds. All are marked on the container and headstamped as H Mk1z.

The "z" in the name indicates that Ballistite is a Nitrocellulose powder, not Cordite. The Ballistite is not only more stable in tropical conditions, but also provides more energy than Cordite can provide in the case volume.

Originally Posted by Tony Smith

.303 Blank cases can be either long or short nosed and are ALWAYS crimped to differentiate them in the dark from Grenade rounds,.....

And what would happen "In the dark" if you used the wrong round?

A Ballistite Grenade launching round used with a Cup Discharger will propel a No36 grenade between 50 to 200 Yards (it has the means to adjust the range). A .303 Blank (which uses Cordite) will only propel a No36 10 yards! This is within the wounding range of the No36. The firing position used when firing grenades means that the firer would not feel the difference in recoil, and in the dark would not see the "flight" of the grenade.

[Tony Smith]

I can't help it!

Geoff Winnington-Ball, when he created this Forum, included some sneaky software called THREADJACKER2000(TM). It causes threads to veer off in random but interesting directions. Do a search for it using the search button to see the results. In a nod to Geoff ( ), it remains an integral part of MLU's program.

We now return you to your regular viewing. Thank you Colin.

[colin jones]

Well I can't answer exactly what type of round it was but I assume it was a blank as I can see it never had a projectile in it. Bruce, I am glad that we had the square discharge style as it would have been considerably more difficult for me to reproduce the cut down SMLE.
Anyway, they are done except for the cable installation which I will do after I get some more information. Even though they are only replicas they are still quite heavy.

[colin jones]

And a few pics of the other brackets now installed in the turret. There's not a lot left to go inside there now.