Reminder for posterity, and safety: work your loads down, not up, and always check for keyholing before mounting your can.
.308 Win Subsonic
16.5" Barrel Rem700
10 twist
Federal LC brass, factory flash hole, full length sized.
CCI 200
10.8gr Trailboss
Sierra 200gr SGK
COAL of 2.810" fits in AICS mags.
Printed a wallered out clover-leaf 5 round group at 100 yards, 5000'DA. Must be running at the ragged edge of subsonic velocity, round 6 produced a sonic crack as it headed down range, but it cooked in the chamber a bit as there was some nonsense going on a few lanes down that stole my attention for a minute. Hate to goof with a load that shoots like that, but tempted to back it down so a warm day or a hot chamber doesn't wreck my suppressed performance.
For the data hounds, I am not measuring velocity, SD, or ES. Just keeping a few rounds in my hunting pack for close range targets of opportunity so as not to spook the game I'm actually after. Was shooting a very consistent 3 mil low and .5 left between supersonic rounds at 100, so 3 up and .5 right becomes my zero offset. Easy squeezy.