In my opinion the very best improvement one can make to the 264 is to lengthen the throat so that one can seat conventional bullets to fit the magazine. The two diameter factory bullet was used so that the rifles couyld be throated to fit the 100 yet use a 140 which was seated long. With a Sierra bullet and the factory throat, the bullet has to be seated very deep. I always thought a 6.5 Weatherby, based on the 257 necked up, would have made a very good cartridge with it's longer neck. GD
