I bought a rf100 from a buddy earlier this year and could never get it to run better than 98-99% correctly oriented primer. It’s as level as I can get it, I monkied with the bushing adjustment, watched all the videos, talked to friends with them etc... and I’d still average 1-2 upside down primers a tube.
I saw someone on Facebook recommend this bushing that entirely crimson makes. The main purpose of the bushing is that it allows the use of the standard dillon pickup tubes, but the ancillary benefit is that I haven’t had an upside down primer since I installed it. Granted it’s still fairly early on (2k rounds loaded) but it seems to have possibly eliminated my upside down primer issue. At least, I’ve gone from 1-2 per 100 to <1 per 2000 at current count.
so if you are having issues with your rf100 dropping upside down primers, it might me worth the $20 to try this bushing... especially with as scarce as primers are these days.