Like I said in another thread the other day, in an auto, there is only so much room to play for OAL when dealing with max lengths. I never try to deep seat a bullet, but I will try for a longer OAL than listed if I can do it and still have my ammo function through my magazines. It lowers pressure, and will usually (but not always) improve accuracy. I use a TC for my auto's too, as do most people, especially if there is no crimp groove.