A friend and I have been piddling around with making a straightwall 40 cal AR cartridge out of the necked up 6.8 SPC. He provided me with some primed cases and I expanded them to 30caliber, then loaded them with some NOE 311284s seated out to the rifling of my Remington Model 14. I used 10gr of 10B101, flake powder from 50BMG plastic training ammo, to blow the shoulder out. It left me a little neck to expand further. I had to single load the rounds and had to use a rod down the barrel to make sure the extractor got over the rim. It shot surprisingly good! I only took 10rds with me and had to walk them up with the first 7rds, but the last three went into about a 2.5" group at 100yds, inside the coffee can lid center of my target. My Model 14 is 109yrs old!