First of all do a search on the reloading forum. All kinds of questions answered there.
I do not crimp for my bolt rifles. 30-06, .303, and .243. So I ignore the crimp groove and watch the O.A.L However, I taper crimp (ignoring the groove) for my M1A .308/7.62x51 as it is semi auto.
If you feel the need to roll crimp, you must hit the groove, and ever so slight or you will deform the bullet.
Also I only neck size for my bolt rifles.
See, now you have more questions!
Get a good reloading manual, like Lyman, and read from the beginning, not just the loading charts.