Proper freebore for .308 win

[gsg5pk]

Normally how to determine the suitable freebore for specific projectile?

I currently using 2013 US-FTR chamber (.170" fb). Most shooter recommend this chamber suitable for 185 juggernaut.

I found that 185 Juggernaunt will touch land @ COAL 3.040"

Then if start with .020" jump coal will be 3.020"


Just wonder the bearing surface will left in neck too shorter than /2 of bullet diameter.

Then with throat erode, we can't seat out to .020" jump as usual.

 

[XTR]

You will never get enough erosion with a 308 for it to be an issue. By the time you do the barrel will be shot out. At least I haven't.

I think I got about .010 in 1000 rounds last time I tracked it on a barrel, there is a lot of room to see further out with the Juggs with that reamer.

 

[jlow]

Normally how to determine the suitable freebore for specific projectile?

I currently using 2013 US-FTR chamber (.170" fb). Most shooter recommend this chamber suitable for 185 juggernaut.

I found that 185 Juggernaunt will touch land @ COAL 3.040"

Then if start with .020" jump coal will be 3.020"


Just wonder the bearing surface will left in neck too shorter than /2 of bullet diameter.

Then with throat erode, we can't seat out to .020" jump as usual.

I just checked mine with the .170” freebore and 185 Juggs seated out about 10 thousands. There was something like 135 thousands of the bearing surface in the neck.

Not a real concern for me as I actually got this setup for the 200 Hybrids which seats much deeper.

 

[usftr]

I actually use a shorter freebore with 185BT and use .170" for 200 hybrid.