On Tuesday, June 25, 2019 at 6:01:14 PM UTC-4, wrote:
On Saturday, July 28, 2007 at 10:16:58 PM UTC-6, Ray wrote:
I'd liked to convert my Montblanc rollerball into a gel ball. I like
the rollerball, but I like gel balls even better. Is there a gel
refill that fits a Montblanc rollerball?

A Monteverde USA Capless Gel Refill will perfectly fit a Montblanc Ballpoint Pen. Can be bought in fine, medium and broad points.

Seconding this, but would also recommend the Schmidt 888 ( https://unsharpen.com/refill/schmidt...erball-refill/ ) for a cheap and reliable option.