the .405 is just a .303 or .30/40 case with straight sides and a bit longer. And there was a .35 WCF that went no where fast but is in the books. Same case necked down for .358 bullets. SO anything that has been done on the .303 British case (alla Mr. Epps) or the .30/40 Krag case by Mr. Ackley and numerous others would be a real guide to what you could expect. This was from the era of 45K CUP pressure standard but that also buys you longer barrel life. enjoy, LUCK