20 practical reamer print

[Coyotefurharvester]

My new AR15 barrel chambered in 20 practical arrived and I assembled the upper. Looking at the reamer print I see cartridge base to end of throat length of 1.993 with a tolerance of 0.005 inch. If I use the fully assembled bcg will I be able to get an accurate bolt face to lands by inverting a flat base bullet, I seated one inverted at 1.994(coal) and rifle would NOT go into battery. Is the fully assembled bcg interfering with getting an accurate cartridge base to lands measurement?

 

[jepp2]

Is the fully assembled bcg interfering with getting an accurate cartridge base to lands measurement?

I will show what I think is the same reamer print. If it is the same, I am reading .193 diameter at 1.993 from the bolt face. I wouldn't expect the bolt to close.

 

[Coyotefurharvester]

Yes I see that is part of my confusion, also I forgot about the ejector. I was trying to find a seating depth starting point without a modified case or a suitable rod to measure a bullet against the lands/bolt face.