The old master H.M. Pope said the bullet base was the "steering end". If any fins or non-uniformity present, this will cause fliers.
So are we saying that the gas check separates from the bullet before it exits the bore?
I thought they stayed together at least until the bullet cleared the muzzle. If that's the case then isn't the gas check acting as the bullet base in terms of Pope's quote? Or is it so thin that the gas pressure will cause it to conform to any deformities in the base of the bullet?