18" Proof Research - 6mm ARC build and testing - factory and handloaded ammo

[Pig_Popper]

Here is what is going in with the 105 BTHP load and my PROOF chamber.

BEFORE CHAMBERING:

   

AFTER CHAMBERING:  I carefully used a cleaning rod down the breach while pulling firmly on the charging handle to get it to unstick without leaving the bullet behind

   

Looks like the hang up is in the area of the freebore based on this cutaway illustration

   

I don't wish to have my current chamber "chased" or opened up, at least not on a $ 500 investment.....