seating depth and free bore?

[uncledillers]

Iam looking to get my first made to my spec barrel some time this year, and want to make sure I cover all my bases.

So my question 2 guestions so far are.
If you were making a barrel to shoot one specific bullets, how far down into a case do you seat a bullet.?I have heard 1x bullet diameter or some 6.5 guys saying .050" above the donut. Is there any advantage / disadvantages other than case capacity?

The second question is what is the desired free bore beyond the ojive. I figure it depends on what the bullets your going to use likes. But is there any advantage / disadvantage if jam or jump if accuracy is the same.

 

[Alpheus]

The 1x bullet diameter is a general rule of thumb. It is mostly so the brass has a good grip on the bullet, you don't want a little rough handling to cause the bullet to go crocked. Seating above where the donut forms simply means you shouldn't need to worry about removing it.
Most folks when they specify the freebore, it is so when the bullet is seated where they want, the ogive is just off the lands.
Accuracy-wise, not really much difference with respect to jump/jam, except for VLD bullets. They are usually very fussy about seating depth.