Over the last 25 years, I have dabbled with just about every 6mm cartridge going. 2 cartridges stand out as delivering the most consistent and stellar results, and I have stuck with them, and keep going backl to them: The good ol' 6BR (.267 neck) and the 6X47 Swiss Match (this is not the old 6X47 based on the 222 rem, nor is is based on the 6.5X47 Lap. It is a somewhere between a 6-6.5 Lapua and an 6 XC)I remember when the 6 Br. Was king, now it’s been dashed, X’ ed , A’ed and a whole more alphabets added to its name. And with each alphabet added to its name the long neck which was the reason they said it was accurate but with each letter add to its name the neck got shorter and the new improved versions still seam to be accurate. Just rambling through’s