Never shot sports or rodeos before so I went and gave it a shot. The lighting was dusk so I had to push the ISO to 800 on my 60D which is in the danger zone for my noise tastes. As a result the speeds were low and this one was at 1/200.
Didn't get a high keeper rate because of the speed, but lucked into a few like this one. I need to get better at controlling noise in post so I can increase the shutter speeds.
I actually have more in the series (dismount etc), its just the low shutter speed I was using blurred things I didn't want blurred. In this one the blurr worked out.
I use the 70-300L as you do but I am fortunate to be in good light an do not have the issues with shutter speeds. Are one of the 70-200 2.8L's long enough?