So, I'm writing this in response to the unfounded idea that a regular transformer from the movieverse couldn't take out a Prime. Specifically, because of Ironhide being taken out by Sentinel. Consider this before you balk at the idea: Why would Bonecrusher attack Optimus in the first film if he couldn't kill him? Why would Starscream or Grindor go after Optimus in the forest battle if they too, couldn't kill him? Why would Shockwave go after Optimus in DOTM if he couldn't kill him? The answer is simple: They could all kill him, and the same principal applies to Sentinel Prime. Ironhide is eye level with Sentinel's chest cavity, which is where his spark chamber is located. One blast from either of his guns would have placed Sentinel in a very weakened position. More so, Ironhide could have grabbed Sentinel's gun, and bought time for the other Autobots to attack him as well. The fact that Sentinel chose to shoot Ironhide in the back is evidence in itself that he was at the least wary of tangling with the old man. There is no reason that Ironhide or any other bot couldn't kill a Prime. Perhaps in the G1 or another continuity there is a basis for this train of thought, but as we have seen the movieverse is not G1.