27 nosler reported to be coming out throated and twisted for 160-170 grainersI can not say anything these people before me have said. I am personally not a fan of the 6mm or 6.5mm slugs. not my thing. I am however; a great fan of the 257's. the 257 Rob/AI, 25-06, 257 Weath, 25 STW, 25 WSM (necked down 7MM WSM), and some of the other really smoking 25's. either the 240 or the 257 weatherbys would make you smile from ear to ear. my go to caliber is the 277. now I hear that the 7 mm RUM has a 277 wildcat and the 308 Norma has a 277 wildcat. My wildcat idea is a 7MM R/M necked down to 277. heavy twist (1:8" or 1:7") and 170 grain Bergers and 150 grain Barnes.