While testing my 270 hand loads of 130 gr. sierra btsp with 59.5 gr of h-4831hs I noticed the velocity kinda low(2860fps from my 22 inch barrel rem) I neck sized with no crimp using Lee collet dies. Does neck sizing and not using a crimp affect velocity? I really shouldn't complain becouse my groups were running from 3/4 to 1 1/4 at 100 yds.