Complete Manual: https://sites.google.com/site/hsarmory/miscellaneous/news/borelappingmanual The v.3L crown enhancers are identical to the v.2s with the exception of being even larger for an even more pronounced crown. These crown enhancers were intended to be paired with first coarse abrasives, or even surface abrasive bonded, and run into the bore slowly from the muzzle end. They are subtly tapered, and so slowly cut away the bore forming the wide and extremely long enhanced crown that has been popular on high end barrels such as the Orga as of late. This tool allows the divorcing of the extended crown from the whole Orga system however, allowing users JUST to test the efficacy of extended crowns. The end of each crown enhancer is keyed to the same square rod as the bore laps, allowing for as deep a crown as the user desires. It is critical that users do not use a single rod for both processes, as they would have contradictory purposes. (one twisting the rod, the other attempting to run a lap perfectly straight) Higher finish grits may subsequently be applied to achieve a true mirror polish as seen below. Care should be taken to apply cutting lubricant, and cool the barrel and tool, as needed to prevent over-heating and thus damage. The only components/tools required for this which is not used with the standard bore lap are a drill press and a second segment of square drive rod. It should be noted that a safety was built into each crown enhancer to prevent the over-torquing of the tool and ruining of the barrel, rod, or injury to the user. The efficacy of this can be seen in the image below, where the keyed end is not present as it has been torqued off. This prevents a catastrophic jamming of the tool in the barrel among other things. Please note this product should be driven only counter-clockwise, as it was designed to, in part because this facilitates the pushing of abrasive and lubricant ahead with the tool and onto the lapping surfaces, but also because the tool should NOT be drawing the barrel down onto itself. While the function of this product has been demonstrated, the effects of an extended crown are still considered experimental.