At the end of August, I won a sporterized 1903 Springfield from a Greg Martin auction

http://www.gregmartinauctions.com/Auctions/AuctionLot.aspx?LotID=7998

My FFL dealer lives a good drive away, so I usually wait till a few rifles have accumulated at his place before picking them up.
I was pleased with this rifle, though not pleased with the $50 shipping fee charged by the auction company.

In looking at the rifle, this evening, I noticed that the serial number 1344306 was electropenciled on the bolt and that the barrel date was 2-30. I don't remember off the top of my head
why some serial numbers were electropenciled on the bolt and the signficance, if any of that. Could someone bring me up to speed on this?