"Most people I have talked to broke their old Auto Prime handles while trying to seat in military crimped primer pockets."
I'm sure that many were broken by people trying to seat in pockets without correctly removing the crimps - who knows what percentage. Thing is, it's clear that many people NEVER break a Lee handle and quite a few more only break one before they learn how to use the tool properly. For the others, I dunno quite know what to say...??
What astonishes me is the number of people who admit to breaking or wearing out a string of Autoprimes, obviously never learning a thing! I really expected better insight from reloaders than that. Failing to lube the toggle link knuckles because there is no written instructions to do so sorta proves my point! (I've always used case lube but most any lube will work.)
I started using Auto Primes around 1980 when I started reloading.
I will admit to breaking one handle but the force I used to seat the primer was only sufficient to get the primer to seat flush are slightly below flush, 0.001-.002 inches or so, as recommended by most reloading manuals. The handle failed over time, several years of use.
And. no, these were not military cases of any kind.
I have had one body fail. Probably for a similar reason as above. The body cracked where the shell holder slid in.
I had one connecting rod wear at the point where it contacted the primer seating stem. The connecting rod was a softer material than the later connecting rods and the seating pin eventually dug into the connecting rod. Over time, it took more and more travel to seat the primer until the handle contacted the body. The later connecting rods where cast of a harder material and lasted much longer.
I had one connecting rod break at the pivot point. I forget if it was one of the soft or hard ones.
All my Auto primes were properly lubricated.
I would have two tools i service at any one time and I would have to buy a replacement about once a year after reloading many thousands of rounds.
Castings as use by Lee in the Auto Prime are inexpensive for a reason. I always considered the failure rate as acceptable, considering the price of the Auto Prime.
I probably have not had a failure of any kind with the Auto Prime in the last 20 years or more. In part, my reloading volumes were reduced, but I can see the parts were better made, the connecting rod for one.
I suspect that folks that have not broken an Auto Prime do not use their Auto Prime much.