Webley MK VI

[jordanka16]

Got a very nice Webley MK VI recently and wanted to share. I also got a bunch of Fiocchi ammo but I also want to cast for it. I have a hollow base MP mold on the way, and I wanted to see if anyone had any data with N320 powder. I have some unique to use but N320 is really my main pistol powder so I'd like to make it work if possible.

https://i.imgur.com/6hqxtej.jpg

[Thumbcocker]

Way cool old revolver. Can't wait for a range report.

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[smithnframe]

What caliber?

[Thumbcocker]

Mark VI"s were .455 unless shaved to accept .45 acp (bad idea).

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[rintinglen]

Given that there is no published data of which I am aware for VV powders and .455 Webley cartridges, you are on your own. What I would do with N320 is, start at 3.5 grains and work up to a max of 4.0, maybe 4.2 grains, I am assuming your boolit will be ~255-260 grains. I would stop when my POI and POA get close.
My own Mk VI is a cut postwar gun that gets 45 Auto Rim loaded with 3.7 grains of Bullseye or Titegroup.

[Baltimoreed]

Target loads for .45acp/autorim should be a good place to look.

[jordanka16]

Mine is still in the original .455. The cast bullets I will use are going to be 260 grain. I was thinking of measuring one when done and using that in quickload to get an idea of a load to use. I'm just wary of overloading them. Starting real low and working up until the POA and POI agree is a good idea. Not too worried about poor ignition with small charges in these tiny cases.

[Bigslug]

Closest thing in the latest (50th edition) Lyman manual is the .45 Schofield, which lists a starting load for N320 at 4.8 grains and 696 fps for the 255 grain Keith 452424.

That's a bigger case and a higher speed than you'll want for a Webley. Rintinglen's post is good advice - I might even dial back to about 3 grains for starters, then proceed as he indicates.

[jordanka16]

Awesome guys, that's super helpful. I'm waiting on some starline cases, mold should be here in a few days and if starline isn't backordered too long I'll get some loaded up with unique and N320 and hopefully find some time for a range trip in between the holiday obligations.

[Outpost75]

N320 is close to Unique in burning rate, possibly a wee bit faster. In my MkVI I load either 3.5 grains of Bullseye or 4.5 grains of Unique with the 265-grain MkII service bullet for 620 fps. If you have access to a chronograph I'd fire charge establishment strings in half grain increments from 3.5 to 4.5 grains and see which groups best, shoots to the sights and falls in the velocity range of 625 plus or minus 25 fps.

[jordanka16]

I have a labradar I'll use for velocity.

Do you notice an accuracy difference between bullseye or unique, and are you using hollow base bullets? My thinking is that the slower powder would be more accurate by one, filling the case better, and two maintaining pressure longer to help the skirt expand and fill the bore after the gap.

Mine has the typical tight .450 throats so I don't plan to try anything but hollow base bullets.

[Outpost75]

Before I had Doug Guy uniform the cylinder throats I used the hollow based MkII bullet. As is common on these, cylinder throats were smaller than barrel groove diameter, not uniform, no two chambers being alike, and the throats were also pitted from wartime use of corrosive primers. After the throats were uniformed diameters were uniform .4555" and most pitting removed. As pinned before the work throats varied from .448 to .452 with barrel groove .455.

After Doug cleaned up the cylinder I ordered a new Accurate plain-based gang mold 45-262H which drops bullets from soft lead .455 as-cast. I get best accuracy with 3.5 grains of Bullseye in the Starline MkII brass.

Unique does not ignite well or burn completely at the low pressures required in the .455 not to exceed 13,700 psi. The Bullseye load was pressure tested by Larry Gibson, has good ballistic uniformity and is safe. This charge should not be exceeded in the Webley top-breaks, but in my 1914 Colt New Service I load 4 grains for 700 fps in the MkII Starline brass or 4.5 grains in modified Schofield brass cut to 0.87" with the rim thickness reduced from the front to .040".

After uniforming the cylinder throats and getting a mold to cast bullets which fit, 12-shot group sizes at 25 yards are under 3 inches, about half what they were before. Firing from sandbags I get 6-8 inches for 12 shots at 50 yards. Combat accurate.

[jordanka16]

N320 is pretty forgiving of low pressure so I'm hopeful it will work well, and like I said I have a lot of it already so it will be nice to not have to use a different powder. If needed I will give bullseye a try though. I may just forgo the use of unique at all.

My revolver has a bore and chambers that look practically new, and the throats are surprisingly uniform, so I'm hoping to have good results with the hollow base bullet.

[Bigslug]

Jordanka16 - I suspect you'll ultimately want a faster powder for that gun. I settled on Bullseye for my MKVI. Unique is WAAAAAY too slow for a complete burn in the .455, IME.

Ideally, you also want a fairly quick pressure peak to pop your hollow base up to groove diameter.

If you haven't seen it yet, stickied up at the top of this handgun sub-forum is our .38/200 Webley thread, in which we go off on significant tangents into the .455, with a link to some work I did with the MP Molds copy of the flat-nosed .455 MKIV bullet. You will probably find all that helpful and informative.

[jordanka16]

You think faster even than N320? I can try and source some bullseye if need be.

I will read through that thread, thanks.

[Outpost75]

You think faster even than N320? I can try and source some bullseye if need be.

I will read through that thread, thanks.

I'm not sure how N320 compares to Unique in burning rate. If faster then try it. If slower I would not hold out much hope. My buddy in italy uses Cheddite Granulare Oro which is a fast-burning, double-based shotgun powder for 12-ga. game loads for 32g of shot at 350 meters per second, burning rate similar to US Alliant Green Dot.

[jordanka16]

N320 is faster than Unique, sort of in between bullseye and Unique, so hopefully it works.

[rintinglen]

Near as I can determine, N320 is pretty close to WW 231 or Hodgdon Universal, so you ought to be okay. I have used 231 in mine, albeit with a 230 grain RCBS boolit.

If you have or can borrow a chronograph, you should be in like Flint, looking for ~625 PSI, as Outpost says, plus or minus a smidge for accuracy and POI/POA concerns.

[Tokarev]

4.2 gr of Universal is a snappy load for my 442 RIC with the historically accurate bullet.

[Kosh75287]

I remember, fondly, shooting one of those, about 100 rounds. I was much younger, and thought that hi velocity was everything. The owner shot two or three rounds into a bunch of old wet catalogs, and then we dug out the slugs. The noses flattened and expanded to slightly over bore diameter. ONE showed signs of tumble. I remember being told that each slug was over 1/2 ounce in weight, and that wrecking balls that topple old buildings don't move very fast, either. I learned.

These days, I covet every one of those revolvers I see. I also think about the tales they might tell, if firearms could be gifted with speech.

[Baltimoreed]

They are certainly man stoppers. Lot of history in them.

[Thumbcocker]

Covet covet

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[jordanka16]

I got my mold today and got some bullets cast up. I measured one and input it into quickload to see what it says. Well I think it can't handle the hollow base calculations very well. It's got a place to enter them but it still came up really off. It said Outpost75s pressure tested load of 3.5gr bullseye would be at 23,000 PSI and nearly 800 fps. So it looks like that's about useless unfortunately.

[Drydock]

If you can find a Lee 1st edition (red) reloading book, it has good load data for the Webley mk ll. I like Blue Dot under the heavy bullet. I also use Accurate mold 45-262m, and have had Dougguy clean up my cylinders.

[Tokarev]

You are unlikely to blow the cylinder, if you approach it conservatively. The worst thing that can happen is a bullet stuck in the barrel. Then you get a bulge and the value of the gun goes down the toilet. So I would start close to 4 gr of Unique or an equivalent load, chrono it and and go up or down one notch, depending on what you see. My RIC's case capacity is considerably less than 455 but the bullet is quite heavy. I already cannot remember what the original Kynoch design drops since I have not shot the RIC in a long time. 240gr? Could be that. All I know is that above 4.2gr of Unique the recoil becomes less than enjoyable. The thin-walled brass that I made from 303 cartridges shows no pressure signs. I can probably get 3 reloads out of it. So for my RIC, I consider this a safe load.

[rintinglen]

293242
This my Mk VI, a high number, post war civilian gun that was cut for 45 acp/AR ammunition. It has Birmingham proofs but no military markings, as well as a 4 inch barrel.

[pettypace]

I was gonna ask if it had been established whether the round nose bullet "tumbled." But then I saw this: https://www.youtube.com/watch?v=VSlnLBcWbHA So maybe not?

[Bigslug]

I was gonna ask if it had been established whether the round nose bullet "tumbled." But then I saw this: https://www.youtube.com/watch?v=VSlnLBcWbHA So maybe not?

We go off into that quite a bit on the stickied .38/200 thread. From what I've seen, the short version on the .455 MKII bullet is that:

1. It's hollow-based, and therefore somewhat drag-stabilized in flight.

2. Because of the hollow base, most of it's 265 grains are in the nose, so it doesn't want to swap ends on impact, like, for example, a tail-heavy M193 55 grain 5.56 will.

I thumped jugs and even a pumpkin - couldn't see anything indicating it would reverse itself even a little bit.

I DID manage to confirm on that thread that the MKI .380/200 bullet WILL tumble on impact, which was a bit surprising to me in that I had previously determined that the very similarly-shaped and weighted Lyman 358430, in trying to duplicate the same load, definitely does NOT tumble.

[Outpost75]

I got my mold today and got some bullets cast up. I measured one and input it into quickload to see what it says. Well I think it can't handle the hollow base calculations very well. It's got a place to enter them but it still came up really off. It said Outpost75s pressure tested load of 3.5gr bullseye would be at 23,000 PSI and nearly 800 fps. So it looks like that's about useless unfortunately.

Using the Oehler 35 PBL with strain gage pressure was under 14,000 psi by actual measurement, not a computed estimate.

Larry Gibson has published his data and methodology which is well documented and calibrated against factory loads.

I don't consider QL estimates to be reliable.

[jordanka16]

Yeah that's what I meant if it wasn't clear. That it was way off with actual pressure tested data so I couldnt really use it for N320 data. I'll have to just wing it.

[jeepyj]

Very interesting post. Thanks for sharing the photo. Another to add to the watch list.