Hi,
I'm doing some reading on reload and accuracy to get my info together for the future... I see that only using brass fired in your own rifle is a popular notion for reloading because using brass that was originally shot in a difference rifle won't suit your rifle as well after you reload it because of difference chamber sizes.
If I had a .308 for example, I would have thought that a .308 is a .308? Regardless of brand or model of rifle, brand of ammo etc. It's all ".308 Winchester".
Why does one .308 rifle (or whatever calibre rifle) have a different chamber size to another of the same thing?