LEE 456-220-1R in .45 Auto Rim cases for Webley MKVI

[earthquake]

I picked up a set of LEE blocks for casting .456" 220gn bullets, I was told they were for the Ruger Old Army BP revolver. I want to try to use them for my Webley MKVI revolver with a .455" bore, I know their a little light for the caliber but I just want to load a plinking load, I was hoping to use red dot powder because I have 7-8 pounds of it on hand. This Webley has been converted to .45 ACP with moon clip but I am going to use Auto Rim cases so as not to use any of my ACP rounds in it by accident.
Any body ever do this? Would 4.0gns of Red Dot sound about right? what would be a good lube to use?
Thanks for any help

eQ

[alfadan]

I loaded the .452 1r in acp cases for a MKvi. 4 grains of 700x is a nice and safe load so I imagine 4gr of RD would work. I crimped in the top grease groove, so case capacity is larger. Last batch were lubed with LLA.

[earthquake]

Thanks alfadan,
I slugged my barrel and it is .455" and so are the chamber bores so I figured that .456" would work well, If I can get something in the 700-750fps I will be happy. I want to see how they drop out of the molds and see what diameter they are before I worry about sizing them, most of my lead supply is pretty hard.

eQ

[alfadan]

My lead is pretty hard too. It's been awhile but I think my bore is .450, but my throats were .449. I think small throats are pretty common for the Webleys. I sent my cylinder to Dougguy and he did an excellent job of honing them to .4525. Accuracy was helped tremendously.
I load them and usually put them in full-moon clips right away, but in case I don't, the long OAL with them crimped in the grease groove makes it nice and obvious they are not my normal ACP loads; and it helps get the bullet closer to the throat.

[Larry Gibson]

Keep in mind the Lee 456-220-1R has tapered bore riding drive bands to fit the tapered chambers of the Ruger revolver. The front drive band(s) are larger than the rear drive band. The rear drive band on my 456-220-1R drops at .452 with 40-1 alloy. The front band runs .458.

[earthquake]

OK I will check that. Thanks Larry Gibson

[Bigslug]

I would second alfadan's post on checking your throat diameters and maybe have Dougguy open them up to something more correct for your groove diameter.

My MKVI is still unaltered .455 and I'm running authentic MKII and MKIV hollow bases out of 4-cavity MP Molds to work appropriately. Your shaved cylinder doesn't have that "unaltered" status, so by having it reamed you'd just be making life easier for yourself.

[willy]

The original MkVI load was a 260 grain hollow base . The tight throats was to create more resistance to better burn the small powder charge( that is what I read) Supposedly the hollow base would expand to fill the bore after passing through the tight throats….Not having any hollow base molds I checked my MKVI cylinder throats and bore,,Cylinder throats came out at .446 Bore was .452,,I reamed the throats at .453 and my groups with 255 grain SWC went from 8-10 inch patterns to 4” groups at 25 yards,,Certainly not a target revolver,,but passible for self defense and a fun gun.