can you really "read" pressure signs from a primer if the pressure is not GROSSLY excessive? I recently read that this technique is flawed for numerous reasons (e.g. primers are harder now than days gone by, etc.)and that there is no real way for the normal handloader without special equipment to tell pressures unless they are truly excessive.

Any thoughts?

As you state, they are over-pressure signs! The first method to get close to judging safe pressures is to use a cronograph to compare your rifles or pistols velocity to that of a load manual, and correcting velocity for barrel length. If you're getting another 100 fps or more, and you're primers don't fall out or look funny, it doesn't mean that your operating within the manufacturers pressure specs for that cartridge.

The more accurate method of pressure measuring is a piezeo electric strain gauge, ala the Oehler 43 PBL.

Reading primers is possible, to some extent, but there are a number of variables, and it takes a lot of knowledge and experience to do it. It is not a "flawed" technique exactly, but not many have the ability to do it properly. Even then, the best you can get is "that is mild", "that is warm but OK", or "that is too hot".

A better technique for the average reloader is to note resistance to primer insertion. With a high intensity rifle cartridge, if you can get three or four reloadings with NO decrease in resistance to priming, the load is probably OK in that rifle. If the primers start to go in a little easier after five or six reloadings, the load is probably safe but at maximum. If you get more that that with no change in feel during priming, the load is under maximum. This is much easier to judge with a hand priming tool, which I use for all rifle reloading just for this reason.

Primer pocket life is a good indication - but I also found out that it goes along with case expansion at the web of the case - just above the rim. Fired factory ammo I have measured usually shows no sign of any expansion from unfired rounds. Hot reloads with short primer pocket life (2-3 reloads) have measured .007" expansion. Moderately stiff reloads that allow maybe 6-7 reloads measure about .001-.0025". Somewhere in one of these posts it was mentioned that Vernon Speer used the criteria of no allowable case expansion permitted for maximum reload data - which would allow longer case life with the neck or case above the web eventually cracking. I can look at the primers (my rifles only) and just about tell how the cases will measure out.

Well I use the same method that rifleman1 uses . I simply have a factory fired cartridge on my bench that I use to compare my own fodder with , havent blown one up yet , so I guess it works .

Rudie

There is an interesting discussion of "reading" chamber pressures in the latest issue of "Handloader" magazine. To summarize the article: many of the classic indications such as a sticky bolt lift, are not accurate reflections of chamber pressures. Measuring case expansion of once fired cases is a useful method; however, none of these methods is extremely accurate. The suggestion is to use the expansion method along with measured velocities to stay in the "safe" zone. Ku-dude