I have looked at some older posts on the benefits of crimping rifle ammo.
There seems to be 2 main camps.
Camp 1 are firmly believing that you MUST crimp ammo that is intended for hunting use, the theory is hunting ammo can get some abuse, partly due to the inertia of recoil which can cause the other rounds that are in the magazine to have their OAL shortened.
Camp 2 seem to firmly believe that any round they make does NOT need to be crimped no matter what the intended application is.
I have been crimping my ammo thus far on all my 270 rounds, I have been using a Lee Factory crimp die. I have been getting some great results.
The next batch I make, I will make 10 identical rounds, half crimped and half not. I will then fire a group of each and see what difference it makes. If I remember I will post some photos of the difference (if any).
I am keen to hear what other people do. I have asked all my friends that reload and the jury is still out for me.