Lyman #454612 heavy .45 bullet info?

[Bitterroot Bob]

Howdy,
I've been pouring lead into some newly acquired moulds and have one old single-cavity that is a a mystery to me. It is Lyman's #454612. This is a heavy .45 caliber bullet. It has two very deep, square grease grooves, a relatively long ogive, and a flat nose. There is no crimp groove. when sized and lubed with Alox, it weighs 298 grains. I am guessing that the bullet showed up in the 1960's or 70's, based on its absence in Lyman's first cast handbook, and only a picture and specs in the second edition.
There is no published data for this bullet, so I'm guessing that it was a special order number. It resembles the LBT design and should chamber in a Ruger cylinder, but is probably too long to function in a Colt, or in a lever-action rifle chambered for the .45 Colt. I plan on seating it over 18 grains of 2400 and seeing what happens. That charge works well for a properly sized #457191 in my Blackhawk.
Does anyone have any history or experience with this bullet? It looks like a real winner.

Bitterroot Bob

[oldrookie]

sounds like a great round for a .50 muzzleloader!

[Bitterroot Bob]

But wait!
It drops out of the mould measuring .455". Surely you don't mean to wrap it in a sabot and sling it out of an (blech!) inline?
With those deep grease grooves it was clearly intended to rub the bore.

Bitterroot
PS: Ooops! I made a smarmy comment about (yuck) inline muzzleloaders. am I going to get Zumbo'd now?

[stuffit]

Similar to this bullet?

s.

[Bitterroot Bob]

These are:
454612, 457191, 454424 lyman bullets

they weigh:
298, 300, and 250 grains respectively

Bitterroot

[Bitterroot Bob]

You can see how large the grooves are relative to the smaller grooves on your bullet and the 457191 45-90 bullet next to it.

Bitterroot

[stuffit]

I like it.   At 0.455, it'd likely shoot well in a couple of old .45 Colt New Service revolvers  I have.   Or in a number of the older .45 Colts with the larger cylinder dimensions.  Lots of possibilities here.
s.

[Bitterroot Bob]

Well,

[Bitterroot Bob]

Don't use the "tab" button...
I shot the 454612 last weekend over 17.0 grains of 2400 from a rest at fifteen yards out of my 4-5/8" Ruger Blackhawk. The recoil was terrific and the short barrel rocked vertical. The first group of five was high, so I dropped the rear sight six clicks and shot another group. Then, I put it aside and shot something else.
This is a GREAT bullet! Why did Lyman cut this mould so many years ago, and why is there no data for it?! I'm thinking I'll go to 18 grains of 2400 and call it good. The cases fall out of the gun and there are no outward pressure signs.
Amazing.

Bitterroot

[oldrookie]

Still sounds like a heck of a muzzleloader load!