After seeing a lot of conflicting information floating around, I decided to do some testing of which PenBBS pens will work with which cartridges and converters. What I found is a bit odd.

Using PenBBS Converters In Other Maker’s Pens:

At least some Lamy pens will accept PenBBS converters (tested with Lamy Aion). You may need to hold the converter with one hand while turning its piston knob – they lack the nubs that hold the Lamy Z24/Z28 in place for Lamy Safari, Al Start, etc pens.

At least some Parker pens will accept PenBBS converters – I am using one in my vintage Parker 45.

Using other converters/cartridges in PenBBS pens:

Here’s where it gets a little crazy! Some models have a narrower inner diameter for their sections and will not accept Lamy or Parker cartridges. Unfortunately I do not have a modern Parker cartridge or converter to test with – maybe someone can volunteer to do the experiment with them?

PenBBS 308 Does not accept Lamy converters – section inner diameter too narrow Might accept Lamy cartridges – didn’t pierce it but it feels like it would fit although maybe not perfectly Accepts modern Parker converters (confirmed by redditor). For the slide converters, it may require trimming a bit off the end of the converter (reported in comments, I have not been able to verify myself). Should accept modern Parker cartridges — the shorter ones at least, and the longer ones may require snipping off piece of plastic from the end (but not tested yet ). It has been reported that they will not be pierced though (I haven’t been able to verify). Ready to eyedropper-fill. O-rings even included!

PenBBS 309 This is a piston-filler, so no cartridges or converters , silly!

PenBBS 323: Accepts Lamy converter Should accept Lamy cartridge (seems like it should work but I didn’t go as far as piercing the cartridge top) Should accept modern Parker converters Accepts modern Parker cartridges — the shorter ones at least, and the longer ones may require snipping off piece of plastic from the end Ready to eyedropper-fill. O-rings even included!

PenBBS 349: Does not accept Lamy or Parker cartridges/converters, section inner diameter too narrow Should not be eyedropper-filled due to metal section (also lacks O-rings).

accept Lamy or Parker cartridges/converters, section inner diameter too narrow PenBBS 267: Accepts Lamy converter Likely accepts Lamy cartridge (seems like it should work but I didn’t go as far as piercing the cartridge top) Should accept modern Parker converters Accepts modern Parker cartridges — the shorter ones at least, and the longer ones may require snipping off piece of plastic from the end Ready to eyedropper-fill. O-rings even included!

PenBBS 350: Does not accept any other maker’s cartridges/converters — inner diameter of section too narrow Should not be eyedropper-filled because it is a metal pen.

accept any other maker’s cartridges/converters — inner diameter of section too narrow

I can mention that I tested with a vintage Parker 45 aerometric converter — unfortunately there’s a band where the converter broadens that will prevent the converter from fitting in PenBBS barrels even if the section accepts the converter

*Modern Parker converters/cartridges don’t have that band so they seem like they should fit if Lamy cartridges/converters fit the pen and the vintage converter fits into the section.