In general, what is the absolute maximum a person could benchpress without using steroids or HGH and the like? I think the record is a little over 700 but I’m sure that guy was using something. I’m guessing somewhere in the 500 pound range but that is purely a guess.
Any answer would be pure conjecture.
Still, there are perhaps-hepful anecdotes out there. Bo Jackson reputedly benched 415 lbs upon arrival at Auburn, without ever having previously lifted weights (not sure this can be cited online … source is a 1990-91 Parade magazine article).
Numbers from before 1935 should be relatively free of steroid contamination:
Are you allowing any special equipment, or do the lifts have to be done au natural? Bench shirts can give lifters a significant boost.
Scot Mendelson, for example, has a personal best bench press of 1,008 lbs with a bench press shirt, but his record without one is just 715 lbs. No idea what his steroid status was.
no bench shirt
The bigger question is not steroids, but shirts. The bench press records are set wearing special shirts, very stiff and precisely fitted. Supposedly, some of the shirts are so stiff that the lifter cannot lower the bar until the weights are added. This, to me, says that the shirt is actually doing more of the lifting than the person wearing it, and I don’t see that there’s any limit on how strong a shirt can be built.
I Said No Bench Shirt!
One of my friends was able to bench just about 500lbs at his peak (he was a defensive lineman in college) and he’s clean. I used to spot him at 450lbs doing multiple repetitions.
While he’s a big guy (6’ 2", 290lbs) he’s by no means the biggest or strongest person out there, so I’d say that 500lbs is definitely a lower limit.
Interesting read: The 1,000-pound bench press.
I’ll say 650 based on the above article. My personal goal is to bench 400.
I read that Paul Anderson could bench over 600 pounds and I don’t really think he used steroids so it seems it is possible.
On edit I don’t think he actually ever benched that much based on further reading but over 500 seems very possible.
Louis Cyr is certainly from the day before steroids, but they don’t mention how much weight he could bench. Is there a way to extrapolate this from his other feats?
Roid rage much?
Puts a whole new complexion on the word “shirtlifter”, no? 
From the article:
I know that guy! I went to school with his daughter.
Did she have a pulley?
Tangent: how the heck does a “bench shirt” work? I’m assuming there’s more going on than heavy starch.
I learned about something new today - bench shirts! Add me to the polite request for an explanation.
An Olympic bar weighs what, 45 pounds? Wouldn’t that be the lower limit? Or closer to it, anyway. I suppose someone could bench press a closet rod.
I can’t find a good explanation of how bench shirts work online, but the basic idea is that they’re very tight in the chest, and that they aid in the lift by pulling your arms together towards the bottom. From what I hear, it’s not like putting on a bench shirt instantly lets you lift another 100 pounds or so. The technique is just slightly different, but enough that you really need to train with the shirt to take full advantage of it.
It’s also interesting that the bench shirt generates so much controversy, when you really don’t hear much about squat suits or the outfits that olympic lifters wear, even though they serve the same purpose. Why? I don’t know.
Lastly, you need to keep in mind that the winner of a powerlifting competition isn’t the strongest lifter, but the one who lifts the most weight under the rules of that competition. If the competition allows bench shirts, then there’s absolutely nothing wrong with using one.
All that said … the difference between the record shirtless lift and “shirted” lift seems to be in the neighborhood of 250 lbs. That’s a heck of an advantage, even if you do have to modify your training.
IMHO, it’s much like having a bunch of guys at the starting line for a marathon … except that they’re all in Formula 1 cars instead of running shoes. Naturally, if cars are allowed in the competition, you no longer have a marathon – you have an F1 race.