As to flattened primers. I find that most factory loaded ammo will show a flat primer, at least in my guns. Contrary to what many think, modern cartridges are loaded to quite high pressures. Probably higher than what most handloaders load to. You need a chronograph to tell where you are on your loads. ShootingChrony has a good entry level one for about $75 or so. They all work on the same principle. Also remember that primer manufacturers use different hardness of metal in their primers. I find that Rem and WW are a bit softer than CCI. I have tried almost all of them and find CCI to be the hardest and give a slightly hotter spark without going to magnum primers. Also a slightly tight chamber will give higher pressures than one that is on the loose end of the scale. The loads listed in reloading manuals are close but not necessarily spot on. That is why they are all slightly different. You really need a chrono to tell what is going on. The WW45JHP econo pak stuff for 22-250, listed at 4,000 fps actually chronographs almost 4,100 out of my 22-250, which has a tight chamber. On the other hand, my 223 handi rifle, which has a somewhat loose chamber will only chrono the WW45JHP stuff listed at 3,600 fps at about 3,450 fps. So get a chronograph and find out exactly where you are on your loads. You are just guessing until then.