So far, I've got about 60 rounds through my new Hells Canyon BAR Mk3 300 WSM. I'm shooting my reloads and figured out that my bullet crimping was too much and bulged the case a little below the shoulder resulting in the bolt not closing completely. I'm using 180gr Barnes TTSX and for my next batch of reloads I'm going to seat the bullet so that one of the groves is under a very light crimp so as not to bulge the case. I'm wondering if anyone has had any problems with bullets moving inside the neck on a BAR when using a light crimp; or even no crimp? My last trip to the range gave a nice 300 yard 3-shot group with 63 grains of Ramshot Big Game powder and CCI magnum primers using Nosler brass. The pic below shows this along with my .243 grouping in the lower right.
Thanks for feedback. I just tried some hand loads without crimp. Loaded up magazine and extracted last round before firing and did not detect any movement of the bullet. 180 gr Barnes TTSX. Picture shows 6-shot group lowers right. 1st shot went high and left possibly due to residual oil in barrel.
I own several BARs I as a rule I crimp all of my rounds that could be used in a hunting situation. I do this to insure that no failure to go into battery and to prevent excessive pressure when the bullet make contact with the lands...that is why an overall length is given. I also use black magic marker to mark the bullet to see if there is contact and I always run hunting rounds through a chamber sequence to insure chambering is effort less. I do not use the bullet seating die to crimp since you may distort the neck or shoulder during the crimping operation.. I use the "LEE crimp er" since it does not put downward pressure on the case only side crimping