Re: School me on hBN
I'm going to disagree with the barrel prep answer.
When we began, I called the tech rep at the Chicago factory. Actually if you want to insure a properly burnished bore you will need to follow a sequence.
The hexagonal shape of the particles have a couple of unique capabilities. It will ingrain itself into the bore and will not strip away like Moly does.
First, to convince yourself of the difference, take your best accuracy load and chrono and shoot at 100 yards.
Perform the same thing after burnishing and impact coating. For projectile impact coating you can check my son's forum at
http://theswissriflesdotcommessageboard.yuku.com/topic/6761 or
http://www.ar10t.com/
follow the sequence. He's been highly successful with the process.
Scrub your bore with Barnes or Sweets, follow with 6-10 clean patches until there's no color. Clean as usual with Hoppes, then repeat the process twice more.
Finally, swab the bore with a .30 caliber swab and <span style="font-style: italic">denatured alcohol</span>. Immediately push another 4 or 5 clean patches through the bore.
Assuming you already have impact coated projectiles and loaded them into cartridges, take a new or completely soap and water washed .30 caliber <span style="font-style: italic">dry</span> swab, lightly dust it with hBN and gently push it through the bore from the <span style="font-style: italic">muzzle</span> end, not the breech. Be careful not to damge your crown. Unscrew the swab at the breech end and then remove the rod.
Now fire your first projectile and that's it. From there you can recalculate your load data since you now have a whole new world of opportunites for different load combos open to you.
If you chrono'd that first round and compared it with the pre burnished numbers you'll find an increase in velocity with accompanying lower chamber pressures.
Once burnished, (despite the claim that you can shoot 3 to 5 uncoated projectiles before the next coated one fired) shoot only hBN impact coated projectiles.
I'll be updating both forums for the interested parties, so if this is of interest you can follow progress of the new project. A Wilson AR10.
My son's 22-250 went immediately after burninghing and projectile coating from a nominal 1" group to an easy .34". Now he's working with new load data getting it even tighter.
As for removing it, just use denatured alcohol, scrub with a brass brush, swab and follow with Hoppes.
zfk55
