I acquired some metal nikon F2 cartridges the other day. They don't look like they would work in a regular camera (I have an EOS 7n, EOS 3 and AE-1). Any experience with these? I'm just now getting into bulk loading film due to the price difference, so these would be nice to use, I have about 10 of them.
You have a problem, you need a Nikon F2 and some Nikkor lenses to make those cartridges work. They are not compatible with Canon and I don't know Canon ever had the equivalent for the F-1.
To get the same thing for (nearly) any 35mm body you need to get the reloadable carts made by Shirley-Wellard in the UK. Long out of production but they still pop up for sale on eBay occasionally.
They're great as they totally eliminate the possibility of scratches from the felt (not that I've had a problem with that...), but yours will only work with the F2 (or maybe the F). They won't even work with the later Nikon F's (F3, F4, etc) or any of the 'other' Nikons (FE, FM, EL, yada yada.)
IIRC correctly, the are the same as Zeiss cartridges (or at least close copies of them).
They should also fit several ZI cameras, probably including the Contax RF (IIRC again, I think they fit the Kiev Contax copy I once had).
They should also fit (are actually preferred for) the Leningrad, as its spring motor is sensitive to drag.
The were also Leica cartridges using the same concept, but weren't compatible.
Unfortunately, the ones I have won't work with my bulk loader & I haven't gotten around to loading them in complete darkness....