I just installed my new 308 SRS barrel on my A1 chassis. Everything seems to go in properly. But when I tried to turn the screw to "lock" the barrel to the chassis, I could only turn the screw slightly more than half way between the "unlock" and "lock" markers on the chassis. According to the manual, I should be able to turn it all the way to the "lock" marker; which is 180 degrees from the "unlock" marker. Am I doing this right?