Powders seem to be coming back on the shelves around here. But with sticker shock.
Like you said before the case is similar to the .30 Carbine. There is three notable differences. The carbine loads are @ 40k psi and a light 110gr compared to your 180gr. The go to powder for the carbine is H110 (WW296). These are magnum powders that like to live in an handgun environment of high pressures, heavy bullets and strong bullet pull.
The unburned flakes of the 2400 indicates a higher load is needed. This might exceed your velocity wishes. Only testing will give insight on this. 2400 is a forgiving magnum powder. Unlike H110 (296). They are definitely not recommended for reduced loads. It is all over loading literature for H110 (296). Some people like Blue Dot. I stay away from that powder except in heavy shotgun loads. It has proven unpredictable in long powder column loads. Even Alliant says that.
I said this before, out of the box thinking would include Trail Boss, AA Nitro 100 and AA5744. Don't forget some of the "shotgun powders" also.
At any rate you are going to have fun with this project. I envy you.
