Does anyone reloading for the .256 Win Mag. I'm in the process of fire forming brass from 22 Jet brass. I would like some suggestion for newer powders!
jcelect

What bullets will you be getting, 60, 87 gr others .... cast GC ??

Do you happen to know your barrel length and twist .....
Marlin or newer rifle .......
since different chamber spec's can happen with these rifles.

1500 to 2,900fps is possible but we will need a little more info, if possibe.

I reload the .256 Win. Mag for a Ruger Hawkeye single shot pistol. I use brass made by Jamison (has a JBA headstamp) and Redding dies. Bullets are Hornady 60 grain flat points. Primers are Winchester Small Rifle. So far I have only used good old 2400 powder but that is mainly because of the scarcity of powder these days.

My reloading manuals only show the old standby's like Unique, Herco, H110, H4227 and 2400. But I would think that AA #7 and AA #9 would be good as they bracket 2400 and Hodgdon Lil'Gun also which is a bit faster than 4227 but slower than 2400 and AA #9 in burn rates.

There was an article in Handloader a few years back but I think it was using a Marlin Levermatic as the test gun. I can't find my copy but perhaps you can obtain a back issue from the publisher.

I have some 60,75, & 87 to start with. The gun is TC 10" barrel. Maybe a 24" barrel is in my future! ? ! Powder is no problem as I load and experiment with many 22 cal wildcats and old cartridges. I'm new to the .257 cal! What range of velocity can I expect from this cartridge? I would like to start with Lil Gun, H110, & 4227. I have used Unique in many revolvers for years but never in a rifle round, what say you?
jcelect

Using 14.5 grains of H2400 which is below max according to the most recent manual that I have which is the Hornady 7th Edition, should bring around 2275 fps with a 60 gr. bullet in the 8.5" barrel in my Hawkeye. I don't have a chronograph though.
Maybe 2400 fps in your TC ?

As you probably know, it is always suggested to use info from the latest manuals that you can get your hand on as powder & primers change over time. What do you have in the way of manuals ? Unique is listed in my Hornady manual and should be good for less than maximum loads in your TC too.

Here is a partial article from Handloader magazine but you have to subscribe to see the actual load data. It does have some very good info though on other aspects of loading that cartridge.


.256 Winchester Magnum Pistol Handloads | Load Data Article

My latest manual is the Hornady 9th edition! I also have older Speers(back to #1), Sierra, Hodgon, Nosler, and many small publications! I was looking for information using the newer powders because the older manuals don't have the newer powders. I also have a large selection of powders from experimenting with 22 wildcats but I'm extremely new to the .257 cals!
jcelect