Looking for info on where to go for good brass for the 7mm remington mag? I am currently loading winchester brass, I cut the primer pockets and deburr the flash holes. I do not weight sort or turn the necks, I've heard win necks are not very uniform, but the brass seems to be working as far as accuracy is concerned. Current groups are under half inch .415 for five. My rifle has a match chamber. Would weight sorting and neck turning improve accuracy? I'm happy with how its shooting now but my main problem is that my neck tension is gone after 2-3 loads. Would annealing remedy the neck tension problem, or are the cases worth all the effort? Where do I go for better cases?