I stand by my origional post, die adjustment is the key to long brass life, but with 30-30 brass so cheap, in a hunting gun will you ware very much of it out??
A DR in NOT regulated to "cross" at any point. It's regulated to have the bbls shoot parallel to each other! A PROPERLY regulated DR will shoot two groups at any given range the same distance apart that the bbls are, at the muzzle.
That olde wives tail about crossing, has been repeated for eons, but that's NOT proper regulation and NOT how any major mfg. regulates a quality DR.
BTW, i shot IHMSA too, and did pretty good, back in the day...
DM