I am in California and have to shoot lead free bullets for hunting. I shoot a 308 with a 20" barrel. Was doing some load development this morning and using up some IMR 4320 44.0 grains I got a decent hunting load at about 7/8" group at 100 yds with the Barnes 168 tsxbt match bullet. Velo was 2520 avg and I was feeling good to go so I shot a few 200 and 300 yds to confirm my drops. I was planning on shooting out to the 400 yd mark on deer hogs and bear and stopping due to my concern with lack of expansion under 1900 fps. I checked my group at 200 yds and found this bullet of mine in the dirt embankment. Do Barnes only open under hydraulic pressure? Impact velocity is 2170 fps. They should open at this velocity right? Any feedback is appreciated