Not really off topic as it has to do with hand priming tools that many of us use...

I used the original Lee round primer tray models for many years. These were what I refer to as the "dangerous" versions, but they were worked better than the later "safe" models and the clear plastic covers weren't prone to breakage like the later square-tray versions. The potential danger of the original round tray models was well-documented by Lee's testing and written up and published both by Lee and in at least one real paper gun publication; long before the Internet so there were no self-anointed sedentary experts involved.

I'm sure many of us that used the "dangerous" models found that after years of use, parts would wear (due to us owners neglecting to lubricate tool parts) and primers would no longer fully seat reliably all of the time.

I finally threw away my round tray Lee's as they were too worn to use. I tried the square tray models which were largely junk and quickly threw them away, too.

I tried two of the RCBS Universals; neither would seat primers with 100% reliability. I returned them. The other RCBS model that used shellholders was a much better tool even if it was more trouble to switch things over.

There are other handheld priming tools out there that have primer magazines; whether or not they also have shortcomings or work perfectly, I don't know, but it's important to make sure you're getting fully seated primers with whatever hand priming tool you use.

For the last couple of years or so, I've used a 21st Century priming tool. Like the Sinclair in that it's expensive and one primer at a time (no magazine but not nearly as slow as some think), it will seat primers properly all the time without attendant problems.