Hi there PP, another one with a happy chucker!
Mj use to projectile a lot too, always before going out and we would have to do a full change! Both of us.
My CMHN told me that if they feed up hill (so lying on you with you semi upright) they have to work harder and are less likly to suck down wind.
I also found that if she started to get fussy at all, if i took her off and burped and then returned to feeding it would be a bit better. Also dont go straight up to your shoulder, can you slowly her up and purp her on your knee? When she is lying the wind or air can mix with the feed and by moving her suddenly it bubbles up quickly causing the massive spew as there is feed caught on top kwim?

Now that she is a older its a bit better, havent had a projectile for mths now, but there is a spew of sorts after each BF (sometimes mixed with solids.)
Now that she is crawling the dog follows her around and cleans up the evidence! lucky we have floorboards.

As the others have said, as long as there is weight gain, wet nappies and no screaming in pain when vomiting, try not to be concerned, it can be scary at times, i remember one time that she got frightened by it and tried to breath while spewing and suched it back in, awwww it was awful, poor little thing.

HTH