Originally Posted by
Juicy
Ive found they shoot quite differently between neck sized and FL sized. I FL sized a bunch of 303 cases, tried some different charges. I found one that grouped really well (45gr of 2209 behind a pulled greek 174 projectile). I then tired neck sizing the fired cases, used exactly the same charge, bullet and stick out and the group was terrible. So yeah I have found FL sized vs neck sized does not shoot the same. Hence why ill now only FL size for that 303, I anneal the necks which will hopefully extend the brass life.
FL sizing really moves the shoulder by a huge amount compared to other calibres so its no wonder the brass might fail quicker