I'm trying to determine a good OAL for my Miha 140gr 9mm boolit. I took a few unprimed cases, belled and deburred the mouths a bit, and seated the boolits with little concern of any swaging as I simply wanted to see how they would chamber.
I noticed at the longer lengths I like to load to, the top driving band engaged the rifling...I think the technical term is the lead. I could easily push the round all the way into the chamber (these boolits are aircooled and relatively soft), but to extract the round I had to use a tool i.e. a fingernail did not seem to suffice. With the boolit seated deeper, it readily extracted, of course.
Is there any danger in engaging the ... I think the correct term is the lead, or would that first driving band need to be a bore-rider to be a safe, full house load with the longer OAL? I'd like to utilize as much of the limited 9x19mm case capacity as I can.
Shorter OAL: 1.129, determined to roughly be the longest OAL with minimal extraction resistance
Longer OAL: 1.152, determined to roughly be the longest OAL without exposing the lube groove