I have had good groups with 300 and 325 grain lead and 300 grain Hornady jhp and IMR 4198. From what Ive read and what little experementing Ive done, the key to regulation of a double is matching the velocity of the original load. I would assume a lighter bullet would require a lighter charge. While the above loads are fun for me to shoot, I was thinking about some novice shooters I introduce to shooting from time to time.

Jim