Tight Bore barrel with Level 10 Bolt on ULE Bodies and XMags

I have read about the trouble using a smaller than .684 (the size of the LX Bolt) on an XMag (tho this may be a problem on anything) since the bolt can't enter the barrel you have to use a larger bore.

I am specificly wondering about the ULE Body. Does the bolt enter the barrel on a ULE Body? If not, there should be no problem with tight bore barrels.

the ULE body uses cocker barrels, so I wouldn't think it entered the barrel.