I have some notes that say 20" 50 gauge hardnose (Duo-Tronic) to fit the 10 Series McCulloch saws but they are not the Oregon D176 mount pattern. They may be Oregon A095?
They are wider than the D176 at the tail and the adjuster hole does not go through to the bar groove like the D176, also the oiler hole does not line up with the oiler on the 10 Series.