spring constants is so small, step 5 need not be taken.

After unlocking occurs, the bolt and the barrel are independent of each other and each is affected only by its own spring. Since the bolt is unlocked, the barrel is no longer affected by the pressure of the powder gases and therefore its free recoil characteristic is to continue moving at the same velocity it had at the instant of unlocking. This is indicated in fig. 2-24 by the fact that the free barrel velocity curve after unlocking is a horizontal line.

The retarding effects of the barrel return spring and bolt driving spring up to the time of acceleration (0.005 second) are determined by the same general method as used before unlocking. However, at the instant of unlocking, the springs have been compressed 0.0414 foot (fig. 2-23). This means that in consideration of the period after unlocking, the initial compression of each spring must be increased by the effect of its spring constant for this (Reflection. That is:

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