I have basically shot out my remmy 5r .308. rIGHT NOW i HAVE A LITTLE OVER 7,000 rounds through the tube. My accuracy is starting to erode and I have been chasing the lands for a while now. I am to the point where I am going to rebarrel my rifle. I am going to sta with a .308 since I have a large investment in theat platform in the form of dies, brass, bullets, etc. I will start shooting f-class next spring. Should I fo with the 155 palma chamber or go with the sammi chamber for 175's? Will the extra velocity in the 155's outperform the extra weight of the 175's? I don't know if it makes a difference, but the barrel is a krieger with the 5r rifleing. When the barrel is installed, I will have the action trued as well. Thanks for the input.