Going Grendel — Erik Cortina Converts AR15 to 6.5 Grendel

Here’s an interesting project — using a second-hand barrel to upgrade an AR15. Our friend Erik Cortina decided to make his AR15, originally chambered in 6.8 SPC, into a 6.5 Grendel. Erik acquired a “pre-owned” 6.5-06 match barrel through our Shooters’ Forum. Erik inspected the barrel with a bore-scope and confirmed it was in good shape after the first few inches (past the chamber).

The 6.5-06 barrel had more than enough length, so he trimmed off the chamber end, then contoured the barrel to fit his AR15. This is a smart way to upgrade a gun without spending $350 or more on a brand new barrel.

In the first video, Erik explains the process of converting his 6.8 SPC AR15 into a 6.5 Grendel: “I take the upper completely apart and pull barrel off which will be used to take dimensions for new barrel. The new barrel will be turned from an old competition heavy barrel. All the barrel reaming will be done using JGS reamers. I will also use JGS reamers to make a seating and F/L sizing die.”

In the second video, Erik contours the “pre-owned” barrel to fit his AR. He uses an old bolt-action 6.5-06 competition barrel and cuts it to 17″ long and contours it to fit his AR-15. The barrel is turned down on a manual lathe to .750″ outside diameter for the majority of its length in order to fit the gas system barrel block that is made for a .750″ barrel. After contouring, the barrel will be threaded and chambered.