Originally Posted by fredj338
YEs, the OAL in most manuals is a tested OAL or minimum. Going below that will increase pressures, loaded longer reduces pressures. So think of a longer OAL as insurance. My point about measuring a factory round is it's a dangerous assumption that it is correct or safe. Load a faster powder, like AA#2 to the top end & then load it at shorter OAL, you are pushing over pressure. Since most powders do NOT build pressure in a linear fashion, there is really no "a little over max". Some powders spike as you go over the top end, some spike badly enough to cause a KB (Clays, TG), so just plugging in a factory OAL can get you into trouble with wrong loads.
what's odd is the OAL provided in the manuals matches one-to-one my factory loads. So, it seems, at least to me the manuals are correct.
I never load above max. If I go beyond the mid point, its at least 2 to 3 10ths of a grain below max (Always). In my manuals, for any given load, the OAL is the same for the minimum to the max load.
So, how much longer should I go? Is there general rule for this adjustment over and above what is listed in the manuals. I am using the Lee (2nd Edition), Hornady (8th edition), and Lyman.