Hello and welcome to the board, try the link posted below for an article on the 414 by Todd Spotti, it has quite a bit of load info it. You can also check with magnum mike @ the specialty pistols board specialty pistols he's shootin a 14" 414SM contender. I've got a 414 barrel sittin in my safe, just need to get some brass ordered and give it a workout. Good luck, hope this helps,
Mark
414 SM article