Started ..... restarted a milsurp . It's a 7.7×58 Arisaka.

Cast bullets ahead.
Casual observations about the cartridge itself . Imagine an 8×57 necked to .310 with a neck only .320 long and a 308 shoulder that loads to almost 06' length . Makes it a lot closer to 06' than 308 . The twist is about 1-9.5" so hurling Volkswagens is possible, if not practical .

The other bug is that this one oversized a fair bit and of course has the round top and bottom Metford rifling, it looks like this ~ but round with 4 lands and grooves . It is .316×.305 . That's cool I have tools and bullets for that . It has a need for .318 to fill the throat . The formed from 270 is going to have to be reamed a .320 makes me force the bolt . It may be a lost cause .
The 8×57 brass is a little better for fit but also short and the shoulder is in the wrong place , too far down .

All minor inconveniences really. The sizing may force me to buy more new dies .