Spiral scratches on bullets?

[1Shot]

The scratches on the bullet are most likely caused by the compound throat that the SAAMI 6.5 Grendel chamber has. You can read all about this in the Volume 1 Grendel handloading handbook on pages 9 & 10. I quote " The Grendel is meant to function in both "Semi" and "Full Auto" models. The compound throat angle addresses accuracy of projectile alignment with the bore while the 0.300 neck diameter enhances feeding reliability." There is more to explain things further. So to sum it up the bullet will slide up into this compound throat before it gets to the lands and thus is being scratched. I have two rifles one with a SS BCA barrel and one with an SS Oden Works barrel and when rounds are loaded and extracted it leaves these same scratches on the bullet. I have rounds that have been chambered a number of times from my hunting trip this year where I loaded and unloaded the rifles a number of times and one of the rounds was chambered once by a full function of the rifle after firing a round when I killed a deer. The bullets are 120 Speer Gold Dot and 120 Sierra Pro Hunter. Both have the scratches and both rifles will shoot sub MOA. The BCA has been very picky as to what it wants to shoot and the 123 SST is the worst shooting bullet in it no matter what load I tried. The Oden barrel shoots well with most anything I have tried but what it really likes will shoot better than I can hold. My hold these days is not consistent dead nuts like when I was younger. I usually pull one out of five shots. The Oden will shoot a ragged hole group with 120 Sierra Pro Hunter for 4 shots but somewhere in the 5 shots I pull one just a might and open up the group maybe to 1/2". The BCA with what it likes hovers 3/4 to 1" with the Gold Dot. Hope this helps.