Using gunfire effects in sony vegas movie studio HD 11

You need to add keyframes to your track motion, so that you can have different track motion parameters (eg position and zoom) for different sections of the track along the timeline.

Get your first effect positioned correctly with track motion, then add a keyframe immediately after it (don't change any settings for this keyframe - it just keeps the position static during the effect.

Then add a new keyframe just before the next effect, make sure that keyframe is selected, and adjust position to suit. Add another keyframe after that effect. Do this for each effect if you have lots of them.

You may find that it helps to have "Sync Cursor" emabled, but be careful that you don't mistakenly add lots of keyframes. Ensure you select an existing keyframe before adjusting track motion parameters to avoid creating new keyframes unnecessarily.

If you only have a couple of effects like this in your project, just use separate tracks (and therefore separate track motion) for them if you can spare the tracks.