Wondering if anyone has worked with this as a starting point for larger caliber, low pressure cartridges? You could start with 50 Basic brass and then neck down to form a series of different cartridges, say in .458, .416, .375, and 9.3mm. Leave a neck length of just over one caliber (like 1.25 times caliber) for a good grip on the bullet.

Would this work to make low pressure cartridges for use in single shot or double rifles? If someone has Quickload handy, what sort of performance can you get out of this setup if the operating pressure is held to about 30-30 levels?

I know there are some similar things out there, namely older British cartridges - holdovers from the blackpowder days that might not be very available any more. 50 Basic brass is pretty easy to get, so it might make a good starting point for a new series of double rifle cartridges. You wouldn't have to depend on special runs of brass this way. They wouldn't be the classic European stuff, but might be very practical here in the US. I think one could easily match 375 Flanged Mag or 9.3x74R performance starting with the big 50 case.

Along that same idea....when using smokeless powder only with break action rifles (low pressure desireable), are there any gains to be had in moving from a regular 45-70 to a 45-90 or even 45-120, keeping barrel length the same at 22-24"? Do these larger cases give you real performance gains if loaded to the same pressure as the original 45-70, or do you end up needing a much longer barrel in order to use any extra powder. I know you can use more powder in a larger case and maintain the same pressure - but does this really buy you anything? Is the gain there only when using the heavy for caliber bullets? So many things pop into your head at night.... thanks, maxman

You can skip .338 and .375. Both have been done, the .338 Talbot and .375 Mach V, respectively. Both would finish a barrel in under 100 rounds, with little performance gain to show for the increased wear.

Urodoji, I think he means 50-140 basic brass.

The Handloaders Manual of Cartridge Conversions lists the case capacity of ehe 50/140 Sharps as
157.01 grs.of water,the .375 Flanged Magnum as 97.21 grs.of water,the .404 Jeffery as 115.88 grs.
of water,and the .460 Weatherby Magnum as 144.67 grs of water.

The .500/.450#1 Express has a capacity of 121.92 grs of water and the .500 Nitro Express has a capacity of 158.28 grs of water.

I have never sectioned a .50/140 to check the web and walls,but the capacity is there to work with.

WC

Go slowly. Increased case capacity helps black powder far more than smokeless. I would imagine you would want to stay at about 2200-2400fps with the standard weight bullet for the caliber. More speed than that and you get stability (during penetration) and bullet failure issues. Once you get past the capacity of the 416/460 case gains come slowly. To keep pressure down it would probably be best to work up to whatever capacity of Re15-Re19 (or 4320-4350) that would get you those velocities. Much slower powders would give ignition problems, much faster, pressure woes. Just my .02 worth.

Right. I do mean the rimmed brass from the 50-140 Sharps type cartridges. Compare this case to the 470 NE case. I don't want to make a new magnum round. 2400 fps with standard bullet weights is all you need, as Blackhawk44 said.

My idea was to create equivalent performance using this readily available case. With this capacity, and keeping pressures nice and low, you can surely equal the 375 Flanged Mag, 9.3x74R, 470 NE, and other larger caliber rimmed cartridges. There is enough room there to allow trimming of the brass to an ideal length as well, to optimize load density. I'd love a double rifle in a classic British caliber, but those components are often subject to limited availability. From what I have seen, the 50 Basic brass is much easier to get.

Starting with this case, you can neck it to 470, 458, 416, 9.3mm, etc and make a whole set of flanged cartridges for any single or double rifle, hopefully with cheaper and easier to obtain brass. The US is definitely lacking in its rimmed cartridge offerings. maxman