Finally got around to running some subsonic 308 ammo over my chrono. I cut back one of my AR-PSR 308 barrels down to about 18 inches and I put my Thunderbeast can on the end.

A spoonful of Trailboss under a Sierra 175 goes about 1070fps and is incredibly quiet. Low ES/SD and accurate. Very happy with the combo.

Now I have something to do with all those 175 pulls I bought.