Replies

1. 
   DonCanDo | Jun 16, 2015 07:42am | #1

   yes...

   Not because the it matters which way the head of the nail is oriented, but because you want the chisel point of the nail to cut across the grain to reduce the chance of splitting.

   Often, it doesn't matter, but for thin materials or when nailing near the edge, like casing, it can make a big difference.

   For nail guns, that means holding the gun perpendicular to the grain of the workpiece.

2. 
   calvin | Jun 16, 2015 08:39am | #2

   As Don mentions....

   It often can split the wood as the head is countersunk.  This is especially true near the ends and edges of trim.