Originally Posted by
chamber143
I have heard that 9310 is supposed to be a lot stronger and a much better performing bolt. I have heard that 9310 can last upwards of 10k rounds were as 158 is 3-5k. That being said I have a 158 that has somewhere around 8-9k and its still fine. Actually all my 158 bolts are still rocking and over 3k for each at least. I love constant improvement and I am guilty of every new improvement to a system automatically means that the previous one is shit now. I feel and have seen multiple testings done that do show 158 lugs shearing well before 9310, just never had it happen in my life. I think if you are shooting a lot of 855 A1 or other very high pressure rounds then there may be a difference, but I think at the rates that civilians shoot, I see it as negligible.