Just bought a Tikka t3 in .270. I am not sure what the lever behind the bolt is. I don't think it moves but not sure. I sighted it in today and have some comments. It is smooth. The barrel cleaned easily for a first cleaning. My son shot a 1" 5 shot group @ 50 yds. I shot a 3.25" 5 shot group at 200 yds. when the barrel was very hot. I fired 54 gr. IMR 4350 / 130 gr cor-loc. With this load it kicks like a mule, but what is that little lever behind the bolt. After 3 shots I had a head ache.