Re: 18” ballistic advantage 6.5 CM barrel
Reply #2 –
There's an old saying, something like, "If you throw enough jump at the wall, one jump will stick out more than the others." Something like that...
Seriously though, @rardoin is absolutely right, and that is the secret to the SMK success as one of the most accurate loads for the 308 ever devised by a manufacturer. I mean, 90% of the guns in the world can't be wrong, and 95% of the guys shooting Federal Match are not shooting "match" chambers with -0.005" jam, you know?
I'd also suggest you drop your powder charge steps to 0.3 grains at a max. I prefer to go 0.2 once I've gotten to within a grain of my preceived/calculated maximum based on my knowledge of how the gun handles max charges with that particular bullet construction. You might find a window in there where you get all the resonant bunnies to jump together and point the pointy thing in the same direction every time it leaves the tube. Good luck!
One more thing, are you sure you can't get those to load out to 2.820"? I get good reliability at that mag length with my Magpul, Lancer, and GI mags.