Crown Question

[amlevin]

Now that I've retired I have a lot more time for projects. One is to re-crown the barrel on my .308 which has a rather rough factory job on it. The barrel measures .810 at the muzzle and has an 11 degree crown.

Now the question, "when recrowning a barrel is it absolutely necessary to do the lapping at the bore?"

Most barrels I see have a slight chamfer where the crown joins the bore, some larger than others. Would it not be just as good if the crown met the bore with a sharp edge provided there are NO burrs or dings? Does this final lapping serve some other purpose or is it merely to remove the roughness from the edge that's left by the machining operation? If the edge is free of burrs to the point that it doesn't catch threads from a patch or cotton from a q-tip is any further finish necessary?

Just wondering an learning.

 

[Preacher]

Some folks do it different but I like the 90 degree crowns cut with a very sharp cutter, lots of oil (Vipers Venom) and cut really slow, with high turning speeds.
Never felt the need to do anything further, figuring if it had any unlikely burrs, the first shot would remove them..

 

[LHSmith]

I would think that without "breaking" the sharp edge somewhat, the sharp edge won't last long with bore cleaning, gas erosion, and routine handling perhaps(i.e. storing a rifle inverted in a safe or inverting the barrel for overnight soaking).