RE: 270 wsm for elk
I bought a box of 150 Winchester Power Points and a box of 130 Winchester Supreme BT when I bought the rifle. Used them to sight in and generate brass that I could reload. I still have part of each box as I quickly worked up a load with the barnes TSX bullets.
I now use those bullets to calibrate my Chrony, Since they are factory loads and I know how fast they are supposed to be. If my chrony reads something different. I know it's set up wrong or the weather is drastically affecting the speed. Once I have a base line with the factory ammo, I can shot my reloads and know the chrony is readding fast or slow for that day.