I've used a variety of priming tools in my 45+ yrs of reloading. When Lee brought out their AutoPrime I thought it was a handy tool.You could feel the primer being seated. There were a few minus's with this tool however. Its cheaply made and doesn't last all that long. For a while they were pretty good about replacing parts but that has long since worn thin. You also had to buy separate shell holders to use this tool. Not a huge problem for common calibres. Just try buying an Autoprime shellholder for the 8x68 cartridge. The other problem is with some of the short fat cartridges. They will not fit into the body of the priming tool. I have a wildcat on an improved 348 case that just doesn't fit.
Next I tried the RCBS hand tool.Much better made but not without a couple problems. While it uses the std shellholders they are a nuisance to change. Having to disconnect then re-connect the interrupter bar. The other minus is the 1/4 inch shaft that seats the primer is not captive in the tool and will fall out if you turn the tool upside down.I've set mine up for belted H&H cases and leave it there.
I recently picked up the new Lyman tool. At least as well made as the RCBS tool. It uses std shellholders which are very easy to change. The shellholders sit up high on the tool and fat cases are not a problem. Linkage is very smooth (at least on the tool I have).
If anyone is in the market for a hand priming tool I suggest you give the Lyman tool a close look.

I have used the RCBS Universal Hand primer for years. No shell holders and will prime my 404 Jeffery and 450/400 3 inch cases. The neat thing about the Universal Primer? The primer tray is. . . .wait for it. . . .square. Just like the trays that primers come in.

Thanks for the report on the Lyman. Nice to know it works well for you.

I'll probably just stick with the Lee Autoprime, however. No matter how many of them I wear out and replace, they'll always cost me less than just one of any competitor's machine. I did try priming a WSM case with the Lee once and found it couldn't be done (well, at least not without doing a little baling-wire-type engineering to modify the tool.) I soon found that there were far fewer reasons to own and shoot a WSM than not, so I solved that problem by passing the rifle along to some other intrepid soul. I suspect that you're exactly right about a .348 rim, or a British 577/450 as well. I'll just have to use my press priming tool if one of those happens to befall me.

By the way, if you'll remember to lubricate the contact points on the Lee tool once or twice a year with Vasaline it will probably last forever, or much longer, at least. Kinda like the old lady in that way, you know.

I have gone from the Lee Auto Prime I to the first Honady Auto Primes. Excellent tool. However, then I wanted to be smart and got the RCBS Auto Prime. Like the gentleman say above it is a mess to change and the pilot that push the primer falls out when you turn the unit upside down. I then got the RCBS Universal Auto Prime. The problems of the orignal RCBS one was solved, but I did found on occation that there was a misallignment of primers due to this universal shellholder system. This could result in the anvil of the primer not being alligned properly or even popping out before seating the primer. I then decided to go back to the Hornady one. It was a new model which has been changed. It works just as well as the first model, but it tends to leave a marking on the bottom of the primer which give you the impression that the primer was crushed. And it is mostly to the one side of the primer. I gave that one to a friend of mine and got another one. Well this new one does the same. I am now back with the RCBS Auto Prime which uses the shell holder. Nice to use, no crushing of primers and the one or two hickups I can live with.

However can anybody tell me if the Lyman Auto Prime takes any brand of shell holder? The Hornady ones only takes Hornady and RCBS and the RCBS preferably uses only the RCBS due to the hight of the primer being developed for their unit.

you guys need to try the bonnzna(forester) tool

Reloader270 I have a mix of shell holders and my Lyman tool seems to accept them all without problems