Getting back to bodybuilding related. Gorillas can curl 800 pounds per a St. Louis zoo study from the 50s:
One useful rule of thumb is the male silverback gorilla. Back in the 50's the St. Louis Zoo rigged up a vertically sliding 'gate' or barrier that could hold weights -- kind of a crude 'Smith Machine' that the gorillas had to move in order to get at their favorite food. It was rigged differently so that sometimes they had to curl it, and sometimes press it overhead. The results? Best eforts: an 800 lbs. curl, and a 1221 lbs. overhead press. Full-grown male gorillas (silverbacks) weigh in at 350-400 lbs. in the wild, roughly 3 times the average wild weight of a full grown male chimp. They are similarly built apes, so a very rough linear extrapolation would have a 130 lbs. chimp military pressing 400-plus pounds. Maybe we should just stop at that conservative, rough extrapolation. But, if we wanted to go further, we could adjust that to reflect the fact that smaller animals are proportionately stronger than bigger ones -- a fact of life in weightlifting and powerlifting as well. Just to be very, very conservative, that would put an average chimp in the 500-600 lbs. press range. Now keep in mind that there are a fair number of bigger chimps, even in the wild, and some real bruisers in captivity who are mostly solid at 200-220 lbs. These guys may be half as strong as a silverback.
The very strongest humans doing a relatively strict 'Smith machine' type overhead press would do, what? 500 lbs? The WSM guys arre thus in the same category as average chimps in upper-body strength. Maybe. So, the 'urbam myths' or whatever, about fantastic chimp strength are exagerrated, but chimps are still stronger pound-for-pound than humans by a significant margin.