Re: Questions regarding loading to mag length
"...is there a specific method that folks follow? I'm assuming that there is some rule of thumb for difference between mag ID and max coal, .."
Well, you know it won't work to have the OAL longer than the magazine. If it's the same length as the magazine it will likely still bind. Thus, the rule, such as it is, is seat short enough to feed without binding in your magazine. And it really doesn't matter how well your ammo may fit in other people's rifles, does it?
I understand you wish a clear set of rules but, other than that there are no rules, everyone is free to do as they wish.