I suppose that there are some "flex", or alleged flex 51 nibs. I'm not saying that there aren't any. But the very design of the nib, more of a tube, works against flex and for a rigid point. What I have seen is cases where the tip of the hood breaks, and the tip is reshaped to a point, which shortens it a bit so the nib extends out farther. When you try to reshape the hood always ends up shorter. Hard to say without seeing how the deep the nib is set in the collector, or comparing the hood length to the hood from another pen, or measuring from clutch ring to the tip of the nib.