5 grains +/- of brass in a 160g case = potentially 3% case volume difference = +/- 1.25 gr of powder in your normal 40g charge = don't load them to max pressure (why risk this in a 99 anyway!!) and you'll be fine.
If You cull out the heaviest and lightest brass and measure every powder charge within .1g you will probably improve your ES/SD across all of your reloads, and win yourself a dead possum!
Thanks Jeff. The lure of the dead possum is strong.
