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Old August 14, 2013, 07:41 AM   #2
Unclenick
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Join Date: March 4, 2005
Location: Ohio
Posts: 21,013
Sounds like you've got the inside and the outside of the bullet confused. Speer has had methods of bonding lead cores to the inside of copper jackets for a long time. Hex form Boron Nitride (hBN) is a dry lubricant somewhat like graphite (sometimes hBN is called "white graphite") except with an even lower coefficient of friction than molybdenum disulfide. This is coated on the outside of the copper bullet jackets, as described here. It basically has the same effects on things as moly-coating, but some like the less dirty hBN better. You can coat bullets, bores, or both with it, same as with moly.

The reduction in friction will greatly reduce copper fouling, but not eliminate it 100%, so using a copper cleaner after shooting these is recommended. I like Boretech Eliminator for this, but you can choose your poison. The friction reduction causes the bullet to be easier to force into the rifling at the throat, like using a sizing lube does with brass cases. This will reduce reaction force during swaging, causing powder pressure to build a little less vigorously than with a plain bullet. As a result, it will typically take a slightly larger (1% or so) powder charge to hit the same velocity with it that you do with an otherwise identical uncoated bullet.

The coating will scrape off easily, same as with moly. I find that to avoid scraping it off the side of the bullet during seating, the case mouth has to be burnished after trimming and chamfering to get sharp edges left by the chamfering tool ironed out. Board member Bart B. pointed out to me that the reverse pitch of an Easy-Out, polished up, will burnish cases well in a regular drill. I have also simply sharpened hard wood dowels like a pencil and turned them in a drill with the point inserted into the case mouth, which seems to work well.
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Last edited by Unclenick; August 17, 2013 at 11:12 AM. Reason: typo fix
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