I just bought some 1916 & 1918 eastons, and the inserts I got from another place for the 1918 ars really tight, I couldn't fit them into the shaft...how hard are you supposed to push on the inserts? They slide in and out of the 1916 loosely, Do I snadpaper them some?
I have had inserts of the right size not work before on aluminums once.One method I use at times is to put a book on a table and position the insert and hammer down on the book with everthing squared up appropriatly.if that does not work sanding may help.thier is a tool you can screw into an insert that looks like a screwdriver.It may help but have never tried one personally.3 rivers sells them.You might try one of those if necessary
you shouldn't have to force them. If you cut your shafts with a pipe cutter, it will cause a little sqeeeze at the point of the cut. If the inserts don't go into a clean cut shaft, then there is a problem with the inserts.