Thx every one for the replies, we store our powder in our basements where it is cool and dry, not much temp changes and the powder is no more than a couple of years old so I should be ok on that front, and we measure every charge on a electric scale and of course every cartage is trimmed to length.
On another note, years ago I shot some 243rds my Grandfather loaded probably 30 or 40 year prior, they all went boom but they were not that accurate and when I looked at them closer I could visually see the COAL was different on every one! Some were like a quarter inch longer than others LOL. Needless to say I was lucky that day.