The Classic Doubles brochure states "Sporter comes with quick detachable stock system and a special 'T' wrench, offering the flexibility desired by competitive shooters". I find a 5mm AF hex fits the bolt perfectly, (no different than my Perazzi) but it won't move by hand torque. The gun functions perfectly, I don't want to make a problem where there is none; if it ain't broke don't fix it. The "quick detachable" makes me wonder if there is a trick here. A 70+ Jeepster, I've been getting frozen screws out for a long time. Is there anything special?