Sorry for lack of detail in first post.
The pen I am looking for is in essence a more durable, refillable version of the uni ball jetstream 101.
I like the pen a lot, as it is also good for maths as well as writing , unlike a fountain pen. However I am annoyed that it is not refillable, and I really just want a pen for life to stop constantly having to buy a new one every 3-4months.

You know you can edit your post, right? You could add the details there because people are already engaged in the discussion.
/just a nitpick
Sorry I’m new
Pilot G2 is refillable. They make a metal body version for like $15.
Is it a gel pen?
Yep. I used multiple for school since the third grade (I’m finishing highschool now). While the pen is great, the refils are terrible. They sometimes dry from sitting for ~2 months and become hard and scratchy (most of my multicolor ones are like this). But the Pentel EnerGel refils fit in the g2 (but not vice versa).
That Uniball looks like a fairly random generic ballpoint pen. I would say go to an office supply store where they have lots of pens on display. Try out a bunch of them and find a refillable one that you like.
I’ve never heard of a ballpoint pen that’s practical to re-ink. You will have to replace a cartridge every once in a while no matter which model you pick.
There are a bunch of fairly standard formats of ballpoint pen refills. Look at jetpens.com for probably more than you want to know.
It looks like there is a whole Uniball Jetstream series, some models refillable:
https://www.jetpens.com/Uni-Jetstream-Ballpoint-Pens/ct/354
On the other hand, the refills are almost as expensive by themselves as the non-refillable model you currently use.


