Bruce, I think what DocM is referring to is a UN edict that is trying to get member nations to reclassify smokeless powder as an explosive and therefore eliminate hand loading in member nations. They would then require special permits and special storage facilities for even small quantities of powder.
Flattened primers are not always a sign of high pressure. Sometimes it just means you have a batch of very ductile metal in the primer cap. It may also mean the batch of powder you are using is slightly hotter than the last batch. Powder and primers both, vary from lot to lot. They are very seldom ever the same. That's a fact of life and isn't something that is advertised but it isn't denied by the manufacturers either. To tell the truth, I'm surprised at how good the quality control really is between manufacturers. The powder you buy in any lot, that has the same lot number, will all be made in one plant in one run and it has all been blended for consistency.
One little trick many of us use is to buy powder in 8lb kegs whenever possible. If we have to buy by the pound with different lot numbers on the containers, we pour them all together in one batch and mix it all together. This will give you one big batch of consistent powder.
When you buy a new can of powder and it has a different lot number from your last can, it may not even have been made in the same country, let alone the same factory. Powder is made to plus or minus quickness factors and so are primers. It is impossible to get the components that go into their make up to be absolutely identical every time. Not only that, it would make powder about 10 times more expensive than it is now.
When you get a different lot number of powder, you should start a few grains below your normal load. I know, for the penny pinched and time pinched, it's a pain in the butt but if you're loading to max pressures, it is necessary. A few grains less than max specs will usually boil down to less than 25 fps in any different bullet weight. Max pressure loads are hard on the rifle as well. They nitride and erode throats which gives shorter barrel life. Not really worth it. As you get older, 25 fps won't seem like much of a trade off. Especially when you have a rifle that is a proven performer and it is one you want to pass on to an admirer.
As mentioned before, there are many factors that create pressure differences. Not all bullet, primers, powders, rifle chambers and bores are made to equal spec. They will usually conform to specified tolerances but could be anywhere in between.
your primers are flat
