but it is a physical impossibility to have all nine lugs touching equally.
When two or more surfaces reside in parallel planes, there can only be one primary locator, or one lug or pair of lugs. The other lugs will simply be the secondary, or otherwise known as along for the ride.
It's just the math and engineering of it all, nothing more.
Not correct at all,just takes time. Have done lots of lapping on other kind of parts.
May take a fair amount of stock removal & a coarse lapping compound with some backward pressure against the boltface (preferably with the barrel off) but it will happen.
As machined/ground, then no, they will not all have equal contact.
