when you exceed the load carrying capacity of your floor, its too much.
I am down too about 20k rounds, I want to buy/ roll more, but with a move coming, its a bad idea.
No...then it's time to revisit the load capacity of the floor joists and invest in some more supports.

When my best friend's father finally had to have all his guns and ammo secured due to advanced Alzheimers, he had at least a thousand rounds per caliber and triple that in the ones he shot the most (not counting .22LR, which was nearly 10,000 alone)... and he owned guns in every standard caliber.
And, he loaded probably 90% of it.