A slightly bent-kneed posture should be more stable, better balanced, and therefore stronger than a locked-kneed posture. However, some people have trouble with bent knees - normally due to knee problems, excessive body weight, or a combination of the two.
But you generally don't see boxers or wrestlers moving around the ring or mat with knees locked; on those occasions you do, those fighters are normally tired and are about to be knocked down or taken down.
Slightly bent knees (partial squat) help lower the hips, and therefore the CG. This should result in better balance. If you apply force to a person or an object while you are off-balance, it tends to move you as much as or more than the person or object. (In fact, a lot of really cool throws result from taking a person's balance as they are attempting to apply a lot of force - IE let them throw themselves.)
Slightly bent knees allow for the quads to come into play, to allow you to move with more speed and power, IE they enable major muscles to apply some spring. OTOH, locked knees take the quads out, and mean forward leg movements are now powered pretty much only by the hips, and upward movement is coming pretty much only from the buttocks. (Edit: relying excessively on hip flexors and extensors, and buttock muscles, is a recipe for lower back pain.)
So, like g.willikers says, this is something to work on. It helps with a lot more than just shooting.