No worries, and sorry! The standard audio engine nodes aren’t loading in the tail of the audio at the right point in time every time, creating the occasional gap. I’m sure there’s a way to do this in UE4… If you’d prefer to stick just with UE4 and not use middleware it might be worthwhile thinking about using the whole sound, spawning a sound cue for each bullet.
If I remember rightly from what I’ve read, this was the approach in Counter-Strike originally and to this day - they fade out or cull the previous sound and play the new one for each bullet.
Have a read about - it can be useful to see how other sound designers working on other engines handled their problems 
In the meantime I’ll come back if I find a UE4-only solution for this - and you do the same please :'D