I have been reading a lot about pressure and what signs to watch for. That got me to thinking about aftermarket barrels. Everyone here says to watch out when using full power loads in a stock barrel, and to be careful of "glock smilies". Some say they went to an aftermarket barrel and the pressure signs disappeared. That may be the case, but the pressure itself did not disappear. If you have high enough pressure to cause a smilie, going to an aftermarket barrel with better support may make the signs disappear, but the pressure is still there. So this leads to my main question. What do the SAAMI specs really mean? If they use a test barrel, how does that relate to the factory barrels and what pressures are safe to use? If I go to an aftermarket barrel and keep working up a load, the first time I may see pressure signs is when the back of the case explodes, so how is that any better then using the stock barrel to see the signs earlier?