Interlocks are not always the most consistent target fodder -- if anything the collet crimp may be helping here. Unless you called it, the flier is likely just bullet run out. I strongly suspect seating depth won't result in truly measurable changes beyond other environment factors. Fire a few 10-shot groups will better show your true bullet dispersion.
I'd tend to agree with all that. Hope was the crimp was helping. Should also mention this is load development for hunting ammo.....so if that is a good result from Interlock's I'll take it.
Do plan to load and shoot several more like it....as loaded and groups of 4 seated incrementally deeper to check for accuracy nodes.
Also finding that the more of these I shoot, the better the results are getting. Like any repetitive sport, practice helps.