Here is a picture of the barrel face on my new Bushmaster ‘pre-ban’ configured A2 profile barrel. I have concerns that the denting and ripples on the flat end of the face of the barrel will affect accuracy. Also I am curious as to what causes this particular pattern of impressions on the barrel face.
Here’s the picture and a description of what I can see up close.
Just outside the upper left corner of the picture I’m holding a flashlight and shining it parallel across the face of the barrel to bring out contrast in the denting of the barrel face.
This is a distinct pattern that looks like the face of the barrel was hammered by something with a large circumference. The face is very
slightly higher at the upper left in the picture – not as higher as it looks, that’s just the light bringing out the contrast.
The 45 degree chamfer is pristine and is in excellent condition (this barrel hasn’t ever been fired). The edge that last touches the bullet as it exits looks perfect. The edge that is the beginning of the face of the barrel looks perfect too except that it extends just a little bit more outward in the upper left area of the picture since the barrel face is a little bit higher there. Here's a very exaggerated picture of what I mean about the champher extending further into the higher area.
When I screw on a Phantom flash suppressor without the peel washer it contacts the upper left of the face first as shown by the transfer of oil. The peel washer I have stops the inside face of the Phantom flash suppressor from touching the barrel face by one half a turn of the FS.
I had another Bushmaster barrel, a post-ban, that had these same large-circumference dents only they were very very slight, and again the chamfered crown area and surface was perfect.
So, my two questions:
1) Will the denting and ripples on the flat end of the face of the barrel will affect accuracy?
2) What causes this particular pattern of impressions on the barrel face?
Thanks so much.