.45-70 data in .458 win mag

The Lyman cast bullet manual show loads for the 458 - that are in the same range as the 45-70 level 2 and 3.
From 1500 to 2100 fps. I used 5744 and IMR 3031 with a 405 grains lead bullet in the 458 - sized .459
You need hard cast bullet - better gas check - if you push over 2000 fps.

Safety wise - rifle data is not interchangeable from one cartridge to the other - even if the data look similar.
 
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Maybe clarify what you are looking for?? A few minutes on Google resulted in several articles for "reduced" loads for 458 Win Mag. Lyman Cast Bullet Handbook (page 227) has loads for 292 grain, 385 grain and 475 grain cast bullets for 458 Win Mag Same book lists more loads for 45-70, but at three different pressure levels, for three classes of rifle actions. Also has data for 450 Marlin, 45-90 Winchester, etc. A 458 Win Mag has about 2.5" case, so would think is sort of "similar" to 2.4" 45-90 or 2.6" 45-100 Sharps?
 
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I am using 3 lyman reloading manuals for cast in the 45/70 and use much of the information to load the 307 gr to 560 gr in my 458 Lott( using 458 win mag, and 45/120 data)
 
Janeau said:
The Lyman cast bullet manual show loads for the 458 - that are in the same range as the 45-70 level 2 and 3.
From 1500 to 2100 fps. I used 5744 and IMR 3031 with a 405 grains lead bullet in the 458 - sized .459
You need hard cast bullet - better gas check - if you push over 2000 fps.

Safety wise - rifle data is not interchangeable from one cartridge to the other - even if the data look similar.
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looking for something on par my lyman cast bullet manual has cast data listed but some of the bullets are of odd weight id like 405gr and 500gr data only 405gr data i found was with trailboss and its a subsonic load
 
From back when I was "playing" with this, I found two useful powders - SR-4759 and 5744. I do not know if either is even made any more?? IMR-4198 seems to be included in almost every cast bullet weight for the various 45 caliber rifles?
 
antiqueguy said:
would it be safe to use .45-70 data in .458 win mag their is not much cast data available for the win mag
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I wouldn't do that with rifle powders, you will be faaaar below minimum start load in that big case.

Use jacketed bullet data that falls within the correct velocity range. 458winmag is an easy cartridge to load cast bullets.

It's OK to use jacketed bullet starting data with a cast bullet and work it up just like a jacketed bullet - but it's not always true going the other way. Cast bullets produce lower peak pressure than a same-weight jacketed or mono bullet with the same load.
 
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I use IMR4198 and a 485gr gas check cast bullet. I used data for 500gr jacketed bullets from Hodgdon 25th manual to get a starting point.
 
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