OMG How do you know Ron??? That is my father!!!  A truly great man, he turns 79 years young in December.  Dad is responsible for getting me started in my love for the 30-40 Krag.  When I started shooting in the early 1980s (right after I enlisted in the US Navy), he educated me on the Krag and the Trapdoors.  When I saw an 1898 Krag sporter in a Mississippi pawn shop, I knew exactly what it was, so I bought it.  He then gave me his 1898 rifle in 1994.  I obtained his Garand this year, and I'm supposed to inherit his 1873 Trapdoor rifle and 1873 Trapdoor Carbine (both currently hang over his fireplace).  I live in Ypsilanti, Michigan. 

My front sight blade slot measures 0.050 using my vernier calipers.  Maybe it looks wide because of the angle and closeness of the picture.  I can always shim the blade if necessary.  I removed the screws from the sight holes by drilling and then using a screw extractor.  I also applied a little heat and used WD-40.  The filed off screws came right out!  The idea came from you, by the way!

Paul