Muzzle velocity Differences between bolt release and cycled round??

[Sinclair]

The name of the game is the same. A bolt released from locked open position does not move forward with the same force as A bolt that has recoiled and hit the "end" of the buffer. Hence the cartridge is jammed into the camber with a different force creating a difference in the amount of whatever of the case during firing. This phenomenon is why auto loaders do not normally display the same level of accuracy as a bolt gun can. Look at the US military's search for a perfect sniper rifle. Trying it get past 800 yards has been a challenge while many of the contemporary bolt guns used by other Nations can reach out to 1200 yards.. Back in the day I had a FAL that exhibited the same phenomenon and yes if the range is great enough the first shot will go low..