I have actually tried that load and it works really well, at least against paper. I used the Lyman 405 grain cast with a full case of uncompressed trail boss. I didn't chrony the load but I would suspect it is moving very slowly, maybe around 1000 fps, maybe less? It was not too terribly loud compared to the stiffer "normal" loads...... Surely not something I'd consider using at anything too far or too big.