55 gallon silencer?

[Ranb]

I built a box out of foam filled steel doors and another muffler out of a 55 gallon drum for use with a 50 BMG rifle. Both did nothing for noise at the shooter's ear but did completely eliminate the side blast and also reduced noise for those nearby. I have a letter from the BAFE what says it is not a silencer.

Ranb

 

[Starter52]

Thanks guys. I'm still looking for more ideas.