IF mag concerns drive your OAL. Start at mag max OAL and come off .010 increments and see what the groups do.
You should hit a point where they tighten then loosen up. In that area you might reshoot at .005 increments if they are not tight enough for you.
Generally most mags throats move about .003-.005 or more with every 100 rds fired, so to maintain same ogive-lands relationship, your seating depth has to move forward the amount of the throat erosion.
The sinclair intl tool, Sinclair Seating Depth Tool, #09-400 cost is $28.95 is the easiest to use for measuring throat erosion and location of the lands. www.sinclairintl.com