The 366 DGW was conceived by David G Walker and is based on the 416 Rigby case necked to .366” (9.3mm) and was developed around 2000 by Judson Bailey from The Workshop in St. Albans, ME. It was developed as a hard hitting medium caliber rifle that will still shoot as flat as the Remington Ultra Mag 7mm’s but taking advantage of the heavier bullets.