VICKERS MK6B's resto

[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]

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]

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?

[Lynn Eades]

To expand on Tony's last comment: Colin's blank is "Boxer" primed while all other examples here, are"Berdan" primed. The Berdan primer is a bigger dia.
FYI. Boxer primers in .303 (post war, commercial?)are generally non corrosive while the Berdan primers of WWII were corrosive.

[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.

[Bruce Parker (RIP)]

Just to complete the record, here are smoke dischargers made out of a Canadian Ross rifle and an SMLE (less the barrel unfortunately).

Both have no safety, either removed, or for the SMLE replaced by a tab that says it's NOT a safety. For safety's sake I guess....

And yes, the crimped round is the blank. I was taking about a ballistite round being different.

[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]

Thankyou everyone for the spent cartridge definition, identification and different types

I am working on the traversing gearboxes and bought some standard gears that are of similar size. Fortunately I have the drawing that is really well descripted and easy to scale.

[colin jones]

Obviously the original was cast but the design is as such that it is relatively easy to reproduce by fabrication.

[colin jones]

The handle on the bottom releases a set of brake shoes which I will find a small set from a motorcycle or similar. It is quite a large reduction of gears so traversing will be very easy. In the manual it says that one revolution of the handle will rotate the turret 3 deg.

[colin jones]

I did quite a bit of searching to find some brake shoes the size I wanted but just couldn't seem to find what I wanted so I decided to make some. As they are very low pressure on little to no speed I thought it would they would be ok.

[colin jones]

The main shoe body is complete, now I just need to work out the tension part with handle.

[David Herbert]

Wonderful !
Are you going to make a radio from scratch ?

David

[David Dunlop]

Hello Colin.

Is the Traverse Control one of the Gunner’s tasks? He must have been a very busy crew member at times.

Not sure if I was reading the drawings correctly but it looks like the brake assembly ties in with the smaller gear assembly. Is it designed as a fully engaged brake that only releases when the turret is traversed? If so, it would only need to be strong enough to prevent the weight of the guns from swinging the turret when the vehicle was crossing uneven ground.

David

[tankbarrell]

The brake is released when you squeeze the grip trigger on the hand traverse handle. This allows you to turn the handle and hence the turret. It also helps prevent the turret moving around.
This system was also used by Powered Mountings on all of their hydraulic traverse systems in nearly all British tanks and was also used by the US in their Oilgear traverse system. That is a very close copy of the PM design and was possibly the only feature of the Matilda II that impressed the Americans!
The main change was the US used iron for the castings, the British boxes all being in bronze. Many of the parts, including the brake and handle assembly will interchange between Oilgear and PM.

[colin jones]

David, unfortunately the radio is way out of my league and not to mention I still don't know exactly what was used in them.

David, your absolutely right, he would have been a very busy boy. The gearbox it located at about 10:00 in the turret and I don't know how the gunner could traverse, sight and shoot at the same time. He could only shoot one gun at once and he would have to lean over quite a bit to fire the 1/2" Vickers and get up very close and personal with the commander. As per your previous comment that it certainly does give you a different perspective what these chaps had to endure.
As Adrian said the brake is only release once the grip is squeezed. I can see that the grip is connected directly to the small pinion gear which is about 7:1 ratio and one turn gives 3 deg of turret rotation. It will be very easy to turn.

[David Dunlop]

Thanks, Colin.

I went back to Post 981 from Jordan Baker. Looks like the last photo of the Gunner captured a bit of a top view of the traverse assembly, down low forward of his left arm. So many bits and pieces to be aware of for the crew just getting in and out of their ‘work stations’.

“JOIN THE RAC! Tall and Portly need not apply!”

David

[Lynn Eades]

That applied to most vehicles. With the U.S. vehicles for example. How many Jeeps, Dodges, or GMCs had seat adjustment? Don't fit= a different job assigned.

[Jesse Browning]

The halftrack seat adjusts. I never had it in any position other than all the way back. At 6’ tall, I had to remove the seat cushion and sit on the steel pan if I wanted to see below the windshield top rail. In the Sexton, the seat had to be adjusted just right in order for my knees to clear the instrument panel, yet still be able to lift my leg high enough to work the clutch, as low as possible to reach the shortened steering levers, but not too low as that made it very difficult to shift, and lastly, be able to see out the drivers hatch. Someone about 5’ tall with massive arms would have done well.

[Mike Cecil]

I've been away for a week or so, enjoying Southern hospitality in Georgia, specifically at the Booth Western Art Museum in Cartersville, and with friends in Alpharetta. A lot warmer in Georgia at the moment compared to Spokane!

Anyway, back to the business at hand ....

Barry Temple's excellent trilogy on the .303 British Service Cartridge, Volume 2, lists 14 different rifle grenade cartridges, 8 use Cordite as the propellant, the others Ballistite (indicated by a z in the nomenclature). The earliest listed dates from March 1915, and the latest, the H Mk.7z, from the 1950s. All except the H Mk.7z have open necks closed with a variety of stoppers such as tallow, fibreboard, shellac and so on. The H Mk.7z had a crimped (closed) neck in similar fashion to the .303 Blank.

I tried to sort out which cartridge went with which grenade(s), but Landers, Bonney and Oakley's otherwise authoritative grenade book frustratingly just states 'suitable [I]blank[I] cartridge' as the propelling agent! (my italics - as Tony has pointed out, the .303 blank does not have the power to project the grenade far enough - a proper rifle grenade cartridge must be used. I'll have to rib Garry Oakley about that next time I see him!).

In March 1935, the H Mk.1z C was introduced, which is the right vintage for use in the projectors on the side of the Vickers. It was superseded in November 1939 by an improved version, the H Mk.1z L.

Edit: I've just had a look at the Matilda handbook, the Matilda having a 'Discharger, Smoke Generator, 4 inch No.2 Mk.1 on the turret side, which I'm assuming is the same type as that on the Vickers - they certainly look the same. The projector fired a Generator, Smoke, No.8 Mk.2/L or 3/L which was propelled by a Cartridge, Rifle Grenade, .303 in, H Mk.1z. A box of cartridges was stowed in the Matilda turret, and eight spare smoke generators were stowed on the turret turntable. Colin: in the absence of a stowage list/diagram, have you detected any stowage mountings in the Vickers that look like they might house spare 4 inch smoke generators?

Great job on the details, Colin, as always!

Mike

[colin jones]

Hi Mike, I certainly have found plenty of holes and funny shaped brackets and it's a on going job to identify and put a name to them. As far as the smoke generator stowage that one is still a mystery to me but I'm sure it will be solved just like all the other have been here.

The traversing gearbox is progressing and I'm understanding the drawings more and more each day. One thing I have noticed when I am under the turret with the gear box and test fitting it, it would have been a real problem when the crew would have been bending down getting supplies from the floor stowage, they would have had to hit their head so many times on the handle. When I get to that stage you will see what I mean.
I have got the brake shoes fitted but need to make the handle and release mechanism before that part is complete.

[colin jones]

It is not exactly as per the drawing I have but its the best I can come up with from what I can see. Once it is all together it will be out of sight but should operate as the original did. I wanted to do more but the last couple of days here in Adelaide have been stinking hot in the low 40s. Not good for the shed but great for a cold beer .

[colin jones]

My traversing gearboxes are progressing well. I needed two small gears that are the final drive to the turret gear so I thought I would have a go and make them. I'm sure it is a very unorthodox method and I had no idea if they would work or even mesh for that matter. After completion I ran them around the big main gear and it was really nice. The teeth meshed with no catching at all so I am a happy vegemite with these. Again they won't be in view once installed but they will work as per the original.

[colin jones]

I still need to machine a stem for the final gear which incorporates a couple of bearings.

[colin jones]

The two boxes are basically complete apart from the mounting brackets.

[colin jones]

I will have to wait until I put the turret on to get an accurate height and location for the installation. They are ever so easy to turn and also very quiet with the grease now packed in. I will fit them first before I remove them for painting.

[Petr Brezina]

Colin, I still believe you have some Czechs in your DNA
The incredible way you made gears is exactly how the Czechs would do it in the emergency! I love your work, great job!

[colin jones]

Thanks Petr, I better Czech my DNA

[Dave lean]

Well you do own a skoda so that sort of makes you Czechish...