My reloading manuals list three loading levels for the 45-70. (Depending on the strength of the action used) The top loadings are a little under what a factory 458 win. will do. I was wondering if the 45-90 case could also be loaded to modern pressure? I have never seen any data listed for this or read of any one trying. Any thoughts or experiences?

JW, the "458 RCBS" wildcat is almost identical to the 45-90, but with a good deal higher pressures. It is made from the same 45 basic cases trimmed back to 2.75"

This wildcat was designed by Huntington of "Huntington Die Specialities" back in the early sixties. I have a double rifle so chambered, and a Ruger No1 as well. With a little careful working up of loads in a RUGER No1, you could squeese some more out of this cartridge,IMO! I shoot my double rifle loads in mine, because it is a scoped back-up for my double! I don't want to boost it much, for fear of getting one of the hot loads in my double!

Huntington's load for this round was:
65.0 grs of IMR4064, behind a 500 gr bullet for around 1900 fps shot out of a Rimington rolling block. I use the same powder load in my double rifle but substituting a 400 gr bullet, for an easy 2150 fps. At only 2100 fps, this load will develope Taylor KO value of 54.

The July/August 1975 issue of Handloader Magazine has an article on this round on page 26, by Ken Waters. This article has a lot of load data. It is also listed in the "Handloader's Manual of Cartridge Conversions" on page 635.

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..Mac >>>===(x)===>
also DUGABOY1
DUGABOY DESIGNS
Collector/trader of fine double rifles, and African wildlife art

MacD37,
Is your double a Pedestoli .45-70 Kodiak rechambered to the 458 RCBS?
If so, how does it shoot?
Did the barrels regulate correctly?
Who did the work & would you recomend him?

Yes, BMG, it is a D. Pedersoli, and it regulated fine, but I was lucky! I have the abillity to re-regulate myself, but in this case I didn't have to! Actually, a better re-chambering would be a 450 NE 3" but you would almost surly have to re-regulate.

My re-chambering was done by:
"Williamson Precision Gunsmithing"
117 Pipeline Rd.
Hurst,Texas
Phone: (817)285-0064

I'm sure he still has the reamer, as he made it from a 458 Win Mag reamer. This chambering job is a complicated job, and should only be attempted by a knowledgable smith. Since it is normal to turn the barrel, and hold the reamer stationary, re-chambering single barrels is a snap by any smith. In the case of a double, however, the barrel assembly must be locked down in the lathe, and the reamer turned by hand, very carefully. The barrel is positioned between centers, then locked down, on the chopper lump with a Mic vice tied to the bed of the lathe, Then the tailstock backed off, the center removed, and reamer installed, then very carefully chambered by hand, for the other barrel the whole process must be done on the other barrel. This requires a lot of expencive bench time, and skill. Mine was re-chambered for just over $200 but I'm a long time customer, and a friend. I'm sure it would be considerably higher than that, but you never know without asking!

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..Mac >>>===(x)===>
also DUGABOY1
DUGABOY DESIGNS
Collector/trader of fine double rifles, and African wildlife art

you can load a good clean Mod. 86 Win, in 45-90 to near 1900 FPS...I've chronographed some factory 458 at a little over 1800 fps. But a good handload in a 458 will claim 2100 or better and with a 500 gr. bullet thats a bunch of difference in killing power...

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com