just my thoughts of other calibers, along with the .338 and .357. Cases were easy to form with RWS brass, and the brass is strong! No longer have the loads for the 6.5X50R Bellm or the 6.5 JDJ, but I was able to match the Bellm to the JDJ, and do it more saftely because of the head size. I'm sure the Bellm could even pass the 6.5 JDJ, with 120 grainers, which I felt was better for hunting. My buddy's 6.5 JDJ brass was actually sticking, while he was trying to match my 6.5 Bellm. I could have probably pushed the Bellm even more, because I've never loosened primer pockets with the strong brass, and could do so safely because the the small diameter head. If and Encore was used I'm sure it would be a different story, but we are talking Contenders. That is the reason I was sort of wanting to stick to the 5.6X50R case in even the .30, .338 and .357 calibers. Just can better utilize the higher pressures "SAFELY", and efficiently. The bigger cases like the .444 and .307 will allow you to use more slow burning powder for heavier bullets, and if that is what you want, then the bigger case will let you shoot them big bullets. Bellm explains some of your questions at his site about the .30 cartridge comparisons. So if your are going heavy bullets for the caliber, then the bigger cases might be the way to go. But I sure liked how my .300 Whisper shot with the 240 Sierra MK, and my .338 Whisper the 300 Sierra MK, and they were going subsonic. Rainbow trajectory yes, but have shot some of the most accurate groups with them. Oh yah, the .300 Whisper was a 1:8 twist, and the .338 Whisper was a 1:7 twist.
Dennis