  We study the spectrum of loops as a part of a complete network of cosmic
strings in flat spacetime. After a long transient regime, characterized by
production of small loops at the scale of the initial conditions, it appears
that a true scaling regime takes over. In this final regime the characteristic
length of loops scales as $0.1 t$, in contrast to earlier simulations which
found tiny loops. We expect the expanding-universe behavior to be qualitatively
similar. The large loop sizes have important cosmological implications. In
particular, the nucleosynthesis bound becomes $G\mu \lesssim 10^{-7}$, much
tighter than before.
