The reverse FMJBT is an ideal shape for flying sub/transsonic, and it will hit a target hard with its bottom-meplat. But it won't expand much as the lead core tends to be of a hard alloy, so yes, go for @shooternz's bullets. These don't come with a boat tail but are flat bottomed as they have the gas checks. Not sure how crucial the gas checks are for sub/transonic loads.
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