Thanks for the info guys. After trying out the-collar button bullets, I realized I go to the same range to shoot collar-button loads and full-power loads. Since I'd rather practice with full-power loads, I listed the collar-button mould for sale.
I understand the idea behind them, but other than economy I don't really have a need for reduced loads. When I was a kid I did: I got the opportunity to shoot one of my first trapdoors on the indoor range used by the local Guard detachment. Let's just say that BP 45-70-500s may be a little overkill on an indoor 25' range. Had I approached shooting on the indoor range with a good smokeless collar-button load at maybe 800fps, it could have been a different story.
But omigod it was funny--they thought something exploded and evacuated the place!