MY ASR kit has these color coded markings with bolts and barrels.... oh wait... is this the Barrett thread? Sorry I belong in the AI thread. I’ll just excuse myself...Regarding bolt head/barrel match marking, Barrett MRAD/Bolt Armor Course, Don Cook recommends engraving matching marks/numbers in non-bearing locations to prevent mixing bolt head and barrels. The four digit codes on the bolt head and barrels appear to be day/month codes of when manufactured. They are matched for head space during assembly, but not finally match coded....up to user. Can't believe Barrett will continue this potential problem for military. Can't see grunt engraving his bolt head/barrel, but sure can see him mixing the components when downrange. It's an issue waiting to happen. Anyone viewed the components in the Deployment kit for match coding??? Can't believe military development team would have missed this.