Field stripping a 905 series Steyr AUG... late 80s style, I take it out for Christmas ;)   The rifle is relatively new to me. Put a few mags thru it, lubed and punched the bore, but never shot it enough to bother a real cleaning.

I don’t think the gas piston was ever removed or cleaned before. In fact, it may never have been cleaned before I got it; pretty scuffed truck gun. Piston caked with carbon. CLP soak on metal parts is helping.

The firing pin is supposed to be pressed forward and turned 90 deg counterclockwise. Looks like not much travel, but it isn’t turning and has a few drops of CLP dripped in to help free it.

Am I goobering this, is there a trick, or is it just stuck with 40 years of residue?

Been a while but just turn fp 90 degrees cc without pressing in iirc

This.

90° counter clockwise

And thanks, that was it. CLP also helped.

Old style with no spring on the pin.

Love my 905 series. Same pin as yours with no spring.

Teutonic master race checking in: