If you go to www.rimfirecentral.com, I think that they have pictures that show the difference between an older 93 and the 93E.

IIRC, it has to do with the diameter of the barrel just forward of the receiver. The older barrels are the same diameter as the receiver and step down about 8" out. The 93E barrels are the smaller diameter for the whole length, no step down.

I had to reinlet my Target-Hunter laminated stock for my older style of barrel.

JEff