New 6.5-284 reloading question

Just built a 6.5-284 using Savage 1-8 twist Varmint barrel. I like to set my bullets to about .02 - .03 off the lands. I am using Sierra 142 gr, MatchKing bullets. Because they have such a long boattail, when I set them there, the case neck only grips the bullet about 1/3 of the way into the neck. I seated them a little deeper than I like just to get more grip on the case neck. I know the barrel is not set out too far as I have the barrel tightened to where it's just a little snug when chambering a new case, but they extract just fine. The nogo gauge indicates there is good headspace. Is it okay to have bullets seated into the case neck just enough to hold the bullet or does that affect accuracy? Does Savage usually make their chambers a little deeper than other barrel makers so that you have to live with some bullet jump? Accuracy is just okay so far, but I'm still breaking in the barrel.

You can seat them out there if you want. I think the old rule of thumb was at least one cartridge diameter worth of bullet in the neck. That rule is more for magazine fed guns than single shots. Is this magazine fed, or single shot?

The Sierra's shot ok for me, but the Bergers shoot better. I seat them out there, my cartridge is long enough that I can't easily extract a loaded round from the port of my target action. I have to press the bolt release and slide the bolt back a little farther.

I'm shooting a McGowen barrel in mine.