Has anyone ever explored the use of very heavy bullets in a 30 Herrett, as in the 300 Whisper? You guys with Quickload got any idea on the charge for a 200 or 220 grain bullet out ot the 30 Herrett case?

Capacity is very similar to 7.62x39 so you might look in that direction.

Unlesss you build it with a fast twist barrel, you aren't going to stabalize those long bullets subsonic.

The case certainly has the right capacity to achieve those results.