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We present semi-analytical constraint on the amount of dark matter in themerging bullet galaxy cluster using the classical Local Group timing arguments.We consider particle orbits in potential models which fit the lensing data.{\it Marginally consistent} CDM models in Newtonian gravity are found with atotal mass M_{CDM} = 1 x 10^{15}Msun of Cold DM: the bullet subhalo can movewith V_{DM}=3000km/s, and the "bullet" X-ray gas can move withV_{gas}=4200km/s. These are nearly the {\it maximum speeds} that areaccelerable by the gravity of two truncated CDM halos in a Hubble time evenwithout the ram pressure. Consistency breaks down if one adopts higher end ofthe error bars for the bullet gas speed (5000-5400km/s), and the bullet gaswould not be bound by the sub-cluster halo for the Hubble time. Models withV_{DM}~ 4500km/s ~ V_{gas} would invoke unrealistic large amount M_{CDM}=7x10^{15}Msun of CDM for a cluster containing only ~ 10^{14}Msun of gas. Ourresults are generalisable beyond General Relativity, e.g., a speed of$4500\kms$ is easily obtained in the relativistic MONDian lensing model ofAngus et al. (2007). However, MONDian model with little hot dark matter$M_{HDM} \le 0.6\times 10^{15}\msun$ and CDM model with a small halo mass $\le1\times 10^{15}\msun$ are barely consistent with lensing and velocity data.

Timing and Lensing of the Colliding Bullet Clusters: barely enough time and gravity to accelerate the bullet