405 at 235 while natural is quite believable. I don't know what he looks like but MCWAY always struck me as a completely life time natural. I was hitting 315 for reps around 200lbs before ever getting on the sauce.
If by lifetime natural, you mean no steroids, no GH, no Clenbuterol, insulin, etc, you are correct.
Let me put it this way: Anything I've used, besides regular food, can be obtained at your card-carrying sports nutrition store in the USA (or at least, it could be at one time).
But, to set the record straight, I didn't bench 405 weighing 235. I was over 250 at the time. To get ready for a fitness run, I started dropping weight. Three or four months later, I was at 227 lbs. I didn't attempt another 405 bench then.
