Reloading the 45 ACP with cast lead , plated , coated or J-word is like taking a walk in the park on a nice sunny day with your beat girl ... who enjoy's kissing you .
Loading the 9mm Luger ... untill you learn all the confounding idiosyncrasies ... is about as much fun as a Root Canal without Novacane ... getting beat with a large stick ... !
The 9mm Luger , with cast boolits is a Stinker ... and will give you trouble at every turn .
If not for tips , hints and directions from fellow members I would have given up loading the 9mm with lead .. I actually said curse words at this confounded tapered cased pain in the butt ... I gave up twice but on the 3rd try ... got a load that worked with 4 different 9mm lugers owned by myself , son and friend . It wasn't easy !!!
I just noticed the OP's question was not about reloading ... but about casting boolits . My Bad ... I jumped the gun again .
Thinking about that ... shorter fatter 45's are no easier or more difficult than smaller diameter 38 / 9mm's ... pretty much a wash ...but I think I might enjoy casting 45 's a little more than 9mm's . I have a Lyman double cavity #452460 that is a pleasure to use ...but I have a 4 cavity NOE 358-124-TC GC 9mm mould that I really enjoy using too ... so it's a wash ... 45 / 38-9mm , six of one , half a dozen of the other .
Gary