Wonder how you press? I have the small arbor press from HF and it works well. I have noticed that it is easy to "press-through" a little misalignment between the part and the blank. Sometimes this resulted in no noticeable issue but I have seen crescent chips like your photo, delamination on printed label blanks and loose fits on other kits.
I now caution guests, because with even a noticeably misaligned cap, final or nib the 1 ton force of the press will still push into the hole, forcing it into line. Unfortunately it may damage other parts in the process.