Look around at higher quality barrel makers. There are several that specify the JP bolt as the reference standard for process control. Anyone can let an out of spec part slip through, but your tip off should be when they try to blame an out of tolerance check of a two part assembly on one of the parts - the one they don’t make.
Bolts don’t “headspace”. That dimension max/min is determined by the assembly tolerances of the chamber/barrel extension (one part) and the bolt (other part). If a combination of some bolt and some barrel fails one of the headspace checks, you don?t know which part is out of spec, only that the assembly failed. If you are building your own, the only way to know with certainty that you are within headspace tolerances is to use a set of go & no-go gauges on your barrel & bolt. For many MSR calibers, you can probably ignore this, but due to the non-SAAMI foolishness that happened previously with this round, you may wish to be certain. Borrow or buy, either works well.
In general, spend money on parts that help you meet your goals. Save money on the others.
I would attempt to persuade you away from bedding your barrel to your receiver with schmutz or whatever. That just makes removing the barrel harder when (not if) you decide to upgrade. If you are willing to spend time and money on accuracy, concern yourself with the barrel quality and who cut the chamber. The other stuff is probably noise.
Bolts don’t “headspace”. That dimension max/min is determined by the assembly tolerances of the chamber/barrel extension (one part) and the bolt (other part). If a combination of some bolt and some barrel fails one of the headspace checks, you don?t know which part is out of spec, only that the assembly failed. If you are building your own, the only way to know with certainty that you are within headspace tolerances is to use a set of go & no-go gauges on your barrel & bolt. For many MSR calibers, you can probably ignore this, but due to the non-SAAMI foolishness that happened previously with this round, you may wish to be certain. Borrow or buy, either works well.
In general, spend money on parts that help you meet your goals. Save money on the others.
I would attempt to persuade you away from bedding your barrel to your receiver with schmutz or whatever. That just makes removing the barrel harder when (not if) you decide to upgrade. If you are willing to spend time and money on accuracy, concern yourself with the barrel quality and who cut the chamber. The other stuff is probably noise.