Sorry, I should research more before I type!
John DOES list a manual for your gun, here, for Plinkers and Duramatic's
http://www.histandard.info/manuals/dura/0274D150R.pdfDuramatic's too are designed for a 6 O'Clock hold on a paper bullseye (at about 50')
If you switch to SV ammo and use a 6 O'Clock hold your elevation problems should be solved!