Need help approximating .380 Mk IIz load with Unique

[Colonel Enfield]

I'm in the process of trying to put together something approximating the .380 Mk IIz cartridge used by the British & Commonwealth in WWII for the Webley, Enfield, and S&W Victory revolvers.

The thing is: Pistol reloading powders are almost unobtanium in Australia (where I am based), and have been for a couple of years now. I have some pre-shortage Unique, but there is no realistic prospect of me being able to obtain other powder - and certainly nothing from the US - reliably enough to want to go through the load development process with it.

One of the projectile manufacturers here makes .358 180gr LRNFP which are close enough for government work to the .380 Mk IIz projectile.

I've got load data with Unique for 200gr LRN projectiles, and 145gr, and 158gr, but there's nothing for the 180gr with that powder.

Things are also complicated by the 200gr loads being everything from 2gr to 3gr of Unique, so while I'm tempted to split the difference and go with 2.5gr of Unique and see how it goes, but I know enough about the cartridge and the powder to know that's not necessarily a good approach.

I'm loading for use in a Webley Mk IV so I don't want cat sneeze loads, but I'm also only using the gun for shooting at targets at a shooting club in pistol matches so I'm not trying to create magnum performance - just recreate the service loading.

Can anyone help?

[Sapper740]

Have you considered substituting black powder for smokeless? Is black powder more readily available in your neck of the woods? I had great fun loading .44 Special with the 246 gr. LRN over a slightly compressed charge of 2F which I used at Cowboy Action shoots for greater authenticity. No pressure worries and if stuck, you can always make your own, assuming the authorities allow you to buy KNO3.

[browningautorifle]

It depends on what you're actually going to shoot it out of. The S&W revolvers will take anything but top break revolvers aren't the strongest...but I never had trouble with the Webley. Rather than spout info only to be asked where it came from, here's a current thread that mentions your cartridge right away. I too use cartridges of the world as one of my reference. If you have loads safe for the 200gr, they won't blow anything up with the lighter bullet.

.38 SW load data

[Colonel Enfield]

Have you considered substituting black powder for smokeless? Is black powder more readily available in your neck of the woods?

Black powder is expensive and dirty, and not what was used in the load I'm trying to replicate, so not on the consideration this for this, I'm afraid.

If you have loads safe for the 200gr, they won't blow anything up with the lighter bullet.

Thanks - I figured the lighter loads would be safe pressure-wise; I'm just more concerned about insufficient velocity or squibs (an issue I've run into before using "conservative" American loads from the internet for cartridges you guys aren't super familiar with like .455 Webley).

[browningautorifle]

"conservative" American loads

I follow you there.

cartridges you guys aren't super familiar with like .455 Webley

I'm Canadian, we have lots of that in our past. I've loaded those too. Never had an issue yet...

[Sapper740]

.....for cartridges you guys aren't super familiar with like .455 Webley).

Webley Mk V revolvers were imported by the tens of thousands into the U.S. and Canada. Some had their cylinder faces trimmed to take .45 ACP with half moon clips but thankfully most were left original. .455 Webley is certainly not an unfamiliar cartridge to Americans.

[jamie5070]

If you are having problems with black powder, I would recommend watching the channel Everything Black powder. He makes powder and tries different sources of charcoal. Compares it to known brands for velocity and clenliness.