My favorite series together with the Hi-uni line.
I’m sorry to inform you, but your PG1505 is almost certainly defective. I have 4 PG1505 and none of them have difference between the length in the lead pipe guide. Took a photo to show:
But, I also have good news. The tip from the PG5 is the same as the tip from the PG1505, so if you have one lying around, you can exchange them.
I’ve been meaning to post about the difference between the versions of the Accugraph, I’ve finally managed to acquire all the 3 versions of the PG2003 I showed in this topic Pentel Accugraph difference between versions. In my opinion, the best one is the first second version, it is heavier with a nice grip. The grip of the first first version is like a limestone, which for me is best, but its weight is lighter than the first second version.