just wear a chest rig or similar, covers the front and a top underneath, I wear a long sleeve top or helikon combat shirts depending on mood and a chest rig to store my mars bar (s), milky bar buttins, phone and car keys in and letter to the wife if something happens, still get hit between the gaps etc, right in the fat meat, it hurts like normal but for seconds like anywhere else, different parts of the body respond differently, wearing a top lose/tight I don't think helps much from my experience as its a bb with 'power' hitting you, you're still gonna feel it....ok I do run into firefights, gotta get the most out of my game fee!
why not try some rugby under armour....dryfit material with padding in places...
i'll show you next time your at tuddenham, sometimes I'm colour blind!!! haha