There were 2 firearms patent granted that day.
http://www.damascus-barrels.com/uspatent.html

This is for a safety
http://www.google.com/patents?id=ugxdAAA...p;q&f=false

This is the American patent filed by Fredrick Beesley
http://www.google.com/patents?id=vAxdAAA...p;q&f=false

I believe it is the 1st patent by Altmaier that the stamp refers to.

Pete