I've been shooting the .38 and .32 versions of the hollow base Berrys and using the same powder charges I use for the same weight of plated or hard cast solid base bullets. So far, I cannot claim any great improvement in accuracy. I'm not sure that any great improvement is possible in the short ranges we shoot handguns---but it's a great marketing tool. I've only shot 100 rounds of the .32 and 150 of the .38 so far.
"If the enemy is in range, so are you." - Infantry Journal