They have the pics correct, sort of. In the transport position, the trails are together, the base plate off and stowed on top of the trailes, and the is barrel locked in place by the bipod under it. In the firing (combat) position pic, the barrel is back as if it is recoiling. Once the round is fired, the barrel comes back to absorb some of the recoil, then slides back forward into the "in battery" position ready to load and fire the next round. The barrel should be all the way forward unless you have just (instantaneously) fired a round. When not firing a round, the barrel is at the "in battery" position, which is 99% of the time.
Also of note, the entire barrel should be bare metal as it is all part of the recoil mechanism, sort of like a hydralic cylinder.
Later version (minor differences) M114, note the unpainted barrel.
Gino P. Quintiliani - Field Artillery - The KING of BATTLE!!!
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