I read that with a pre WW2 Mannlicher one could depress the trigger with the bolt open and back, and that on lowering the muzzle gravity alone would cause the bolt to close and lock. Out of curiosity I tried this with my 1961 MCA. Apparently not all the MS craftsmanship was lost after the war, it did in fact close and lock. The more I research and use mine the more intrigued I am.