458 MCW Express

295 Views
Last Post 29 November 2020
Topic Is Solved

Standard Member

cztrouba posted this 26 November 2020

Hello

I am looking for cast bullet loading data for the 458 MCW Express.

It is a full length 375 H&H blown out to 458. (designed in 1953 by Macfarland, Corbett & Wells all of prescott, AZ)

The manuals I have do not list this cartridge or any of the similar cartridges like 458 Lott, Barns, Watts, Mashburn or 450 Ackley Magnum using cast bullets. Ackley's Handbook vol 1 shows some maximum loads for jacketed bullets but nothing cast.

If anyone is loading for this cartridge or can suggest somewhere I can look it would be appreciated.

Thank You, Bob

Attached Files

10 Comments

Order By: Standard | Newest | Votes

CBA Member

bushranch posted this 28 November 2020

For my .458 shooting I consider the round to be a 49-90 belted and go from there. Bullet weight kept under 400 grains and 14.0 to 18.0 grains of Unique is a good place to start. Rus

Attached Files

Liked by

CBA Member

admiral posted this 26 November 2020

I shoot cast through two different .458 Win Mags. There's no reason you couldn't use load data for .458 WM out of a Lyman manual.

Attached Files

CBA Member

RicinYakima posted this 26 November 2020

I have an original Harvey Anderson 450 Watts, 375 H&H full length case and expanded to .458 with no neck, straight sided. I have two loads developed; Lyman 459193 with 18.0 grains of Unique for 1100 f/s and a Hoch 500 grain bullet with 34 grains of SR4759 for 1450 f/s. Both of these are less than starting book loads for 458 Winchester, but have worked well for me for 10 years.

Attached Files

Standard Member

cztrouba posted this 27 November 2020

Patrick and Richard

Thank you for your reply

I will look at 458 win mag and see what I can come up with.

I have a 457193 mould that I tried today using a load from the records of the man who built this rifle, 52gr IMR 4064 and lyman 457193 bullet. I was only shooting at 50yds but 4 shots grouped a little under 1" with the 5th opening up to 1 1/2".

Thanks again , Bob

Attached Files

CBA Member

RicinYakima posted this 27 November 2020

You are welcome, Your load kicks too hard for me to just plink rocks. Big bores have always been accurate for me, just don't have a use for them now other than fun.

Attached Files

Standard Member

cztrouba posted this 27 November 2020

Richard

You are correct recoil is not light.

Do you use a filler in these loads and if so what and how much?

Thanks, Bob

Attached Files

CBA Member

Larry Gibson posted this 27 November 2020

I would not recommend the use of any filler with the fast burning loads [Unique and 4759] or if any similar fast burning powder is used.

If the 4064 powder load is less than 80% load density then I suggest a dacron filler. I'd also recommend a GC'd bullet with such a load if shooting further than 50 yards is contemplated.

LMG

Concealment is not cover.........

Attached Files

CBA Member

RicinYakima posted this 27 November 2020

Bob, I choose those powders because they do not require a filler. A large rifle primer has plenty of ignition for both, and fillers are another complication. Since I shoot these off hand, after I load the cartridge I bring the rifle up to port arms and position the powder to the back of the case. Then I sight the rifle and fire. HTH Ric