This is an interesting challenge. I’ve got an F5, and I also have a roll of exposed film that was inside an old bulk loader I purchased a while ago.
Here’s some things I experimented with:
1) I took 12 feet of film and wound it onto a core spool. The film was larger in diameter than the spool flanges, and when I tried to put it in the camera it wouldn’t fit. This was without the canister.
2) For the next test, I used 9 feet of film on the core spool. The film was still larger than the spool flange diameter, but this time it just barely fit in the camera without the canister. When I pulled the leader forward, and closed the back, I would almost always get an Err message on the screen. It obviously didn’t like something, and wouldn’t advance the film. I tried this several times and kept running into the same problem. I finally took a regular test roll in a canister, and that roll started fine. After that roll got to frame 5, I turned the camera off, and swapped in the long roll without the canister. This time it started winding. I discovered that the counter will count up to 39, but it will continue to advance the film after that. I didn’t keep track of have many additional shots I was able to take, but eventually I got the END signal showing up in the display. At that point I opened the back, but noticed that there was still a lot of film that hadn’t been advanced yet. I puzzled about this for a bit, and then realized that the take-up spool had filled up, and there simply wasn’t any way more film could be advanced.
3) I cut the film length down to just over 7 feet, and the film diameter was about the same as the spool core flange diameter. When I put this in the camera I was able to get 51 shots, but the counter stops counting at 39. I still had problems loading the film on just the spool core. Sometimes it would work, and sometimes I got the Err message when trying to advance the film. I put the film in a film canister and it seemed to fit O.K.. When I loaded the film in the canister I didn’t have any problems getting the camera to advance the film. I’m guessing that when the film is loose on the spool without a canister, it doesn’t seat properly on the sprockets.
My final take is that it would be a nightmare to try and load film in the camera without the canister. I was doing this in daylight, and it almost never worked properly. Trying to do this in a changing bag would be next to impossible.
I ran just over 7 feet of film in the canister, which gave me 51 shots. I could probably get a little bit more film in the canister before it bound up, but it probably wouldn’t be much more. I don’t know what type of film it was, but it was something of normal thickness. The camera did advance the film its full length, so the takeup spool can handle about 7 feet of film.
The film you’re using is thinner, so I’d expect you can get a significantly longer length of film in the canister. I think it would be reasonable to assume that the camera will keep advancing as long as the film can physically fit in a regular canister. I think it will crap out if the takeup spool gets filled or if it senses the force to pull the film is too high (end of roll). I can’t be certain of this, however, since I didn’t actually test beyond 51 shots.