Can More Be Less? CORBON .223 77gr MPR (TMK) 20" Barrel Gel Test
This video tests the CORBON .223 77gr Sierra TMK (Tipped Match King) from a 20-inch AR-15 barrel into ballistic gelatin. Contrary to the common misconception that higher velocity always means deeper penetration, the test reveals that the increased velocity from the 20-inch barrel caused the TMK bullet to fragment excessively, resulting in shallower penetration (9.5 inches) compared to its performance from a shorter barrel. The instructor recommends this bullet for shorter barrels in home defense scenarios where over-penetration is a concern, but advises against it for longer barrels due to its fragility at higher velocities. For longer barrels or situations requiring barrier penetration, bonded soft-point bullets like Fusion or Bear Claw are recommended.












