what about a 45/70 x 1 1/2" for a 458" bore?

[alan in ga]

I keep looking for a Contender idea that will give a .458" bore [not .451-.452"] and not have the excessive powder chamber of the 45/70. Thinking a shortened 45/70 case would be nice > .45/x1 1/2".
know of one?

[MePlat]

Other than just having one what would be the advantage?  The 45/70 can be loaded down to do the job of the smaller cartridge.  
It would be something nice though.  I like things that not everyone has too.

[alan in ga]

better powder burn with less empty space in case. Pistol and low power loads for Marlins and Contenders don't need all the space. A more efficient burn maybe? I'm applying this to 14" and shorter barrels. Reduced loads don't always give good efficiency with air space in case over powder.
Thinking out loud.
alan in ga.

[MePlat]

While I have never loaded the 45/70 way down I don't see why it wouldn't work well.  the cartridge has for years performed very well loaded to as low as 16000 psi and its record is beyond reproach.
Accurate Arms list several loads for 5744 that should get you down where you want in velocity.
Efficiency is well and good but as long as one achieves the desired goal of the target velocity that is really all that matters in the grand scheme of things.  
I am with you that the less powder will be more efficient on the old billfold if one is going to shoot alot.
I believe someone did shorten the 458 to something like 1.5 inches one time and I think it is in cartridge of the world.  Maybe one could do some extrapolating and determine what a 45/70 would get cut to the same length.

[newhh]

In the Gun Digest Book of Handgun Reloading by Dean A Grennell and Wiley M Clapp you'll find a section devoted to Contenders. In this section is a listing for a 45 Silhouette developed by Frank C Barnes. This is a 45-70 shortened to 1.5 inches. There is also a little load data for 300-gr. bullets in 20 and 12 inch barrels.