[Vpmedia]

I think to increase volume of Browning MG sound, you'll need to open weapon.MGunBrowning50s.prs

[common]
mode relobj pos
type mixer
numadj 1

[spl]
130

[samples]
MG_Browning50x.wav
MG_Browning50.wav

[sample.MG_Browning50x.wav]
env 0 2
infinite 1
period 0.074

[sample.MG_Browning50.wav]
env 8
infinite 1
period 0.074

the one you need to adjust is spl (between 100-120 is normal, 140 is loud imho)