The new and improved Fat Mac cartridge.

[coyoteking]

Kelly McMillan is working on an improved version of the cartridge his dad built in the 90’s. It looks like an interesting idea. I don’t know if links to Facebook work here so I snapped a couple of screenshots to post instead.

 

[hunter5425]

Might be a bit light for elk, but should be fine for coyotes.

 

[Big bore dinosaur]

Can I get that chambered in an ultralight rifle

 

[Scotty454]

That's a crazy looking round, haha. What's the bullet diameter? And the burn column, is that just to allow the primer flash to provide more even ignition of the powder?

 

[Ganderite]

Looks like it uses a 308Win as a primer.....