10-08-2019, 01:47 PM
(This post was last modified: 10-08-2019, 07:34 PM by lazyengineer.)
just_john Wrote:There is another consideration for lapping, it not only trues the barrel to the receiver, but it also helps to insure that all of the bolt lugs have the same ( or nearly so ) bearing surface area in contact with the extension lugs. This will go a long way to mitigate premature bolt failure.
That wasn't really my experience as being a need. With the PSA upper at least, it came from the factory quite square.
As to lapping being "easy", it's doable to an enthusiast who has all the right tools and gumption. I don't consider it a reasonable expectation for this to be a normal part of ownership for everyone to do. And that's one of the challenges of Grendel; it's pushing some engineering boundaries for the purpose of delivering impressive performance. But no other round has people encouraging lapping over fear of breaking bolts if you don't.