08-29-2011, 01:16 AM
FWIW, there really isn't any user way to adjust headspace. They make bolts to one spec, and the headspace is controlled by the barrel extension. Individually headspaced bolts are highly likely to be a marketing gimmick in the vast majority of cases.
If you buy a barrel and extension that is made to Grendel spec, and you buy a Grendel bolt, then you have components that are theoretically in "spec" with each other. No one (to my knowledge) offers off the shelf bolts that are +.001, +.002, etc. etc.... They just are what they are. If they are both Grendel, and for some reason they don't match, then it is because one was made incorrectly and needs replaced with one that is in spec.
If you buy a barrel and extension that is made to Grendel spec, and you buy a Grendel bolt, then you have components that are theoretically in "spec" with each other. No one (to my knowledge) offers off the shelf bolts that are +.001, +.002, etc. etc.... They just are what they are. If they are both Grendel, and for some reason they don't match, then it is because one was made incorrectly and needs replaced with one that is in spec.