They headspace with JP bolts, so use a JP bolt if you don't want to ensure proper headspace yourself with a different brand. That's all they mean by it. If you have the go, no go, field gauges and non-jp branded bolt checks out ok then you are ok. they wrote this whole thing about jp being consistent so they use them so you don't have to send them your bolt to headspace to. Any quality bolt within spec should work just fine, there is nothing special abut the JP. As with any new build ensuring headspace is recommended (even if you use JP bolt)
You could use the maxim bolt Vascar mentioned with the krieger, just ensure the headspace is within spec (99% it will be, maxim is pretty good quality and uses same materials as the JP which is some special steel they use in f1 transmissions)
The go/no gauges run $40 each on brownells so potentially add $80 if you want your own gauge set to verify headspace with.
If you do decide to go with a krieger, expect a long wait time, spending money, and a very spartan package when it arrives. You will get a box with the barrel inside and an invoice. Not even a sticker....
You could use the maxim bolt Vascar mentioned with the krieger, just ensure the headspace is within spec (99% it will be, maxim is pretty good quality and uses same materials as the JP which is some special steel they use in f1 transmissions)
The go/no gauges run $40 each on brownells so potentially add $80 if you want your own gauge set to verify headspace with.
If you do decide to go with a krieger, expect a long wait time, spending money, and a very spartan package when it arrives. You will get a box with the barrel inside and an invoice. Not even a sticker....