I'm gotten really interested in a nice precision rifle lately and I'm considering 6mmbr. I want to use it from 600m to 1000m, (I have read there are "better" calibre's for these distance's but all in all I think 6mmbr is best for me) so I'm thinking 105-107 gr bullets with an 8 twist barrel. One thing I keep reading is to match your chamber to the bullet you will be using. But how do you decide? Do you pick one bullet and get it chambered to match that bullet, or does the chambering match a range of weights. I've tried researching the answer, but I'm not sure I'm asking the right question. I'm still very new to this precision stuff. Thanks for any help.