Note the Extreme Spread. With your annealed loads was the ES any lower?
ES was almost cut in half, next chrony session I'll shoot a larger control group for a GOOD comparison.
Ahhhh. I think this is the Achilles heel of the BLK. It is very unforgiving as a hand loading round. Factory ammo may be much more consistent, but when hand loading the bullet pull seems to really effect the ES, making it unforgiving.
I now anneal my brass each reloading making the bullet pull more even. I have never run into a round that is so temperamental as the blk. But in all practicality since it is mostly a <200 yard round it makes little difference.
The more I reload it and the more i shoot it, the more I realize the BLK's limitations, and benefits. It's no 6.5 MPC. The BLK is by far a better subsonic round. I shoot a lot of subs. So the blk works for me. However if I was hunting with supers I would go 6.5 MPC for sure. I reload only so the MPC not having factory ammo is meaningless. The flatter shooting higher energy of the 6.5 MPC makes it an obvious choice over the BLK if and only if subsonic shooting i not on your menu.
But I shoot a lot of .30, so the BLK gets a lot of press time. If you are not shooting subs, then you might benefit looking into the 6.5 MPC. I shoot a lot of subs so the BLB is a better choice for me.
Lil Gun sure seems to be a good powder for the BLK!