I too find the Presentation Targets a bit big , but Magnas don't fit my hand either and are way too small to handle any recoil. I did like the seemingly smaller , earlier Diamond Targets from the late 50s - 60s and of course , the 'Cokes'. The S&W factory 'fingergroove combat' grips are also an improvement.
Most of my revolvers get Hogue hardwood monogrips. They fit like they were made for my hand.