Not for 5.56, and the design of the cartridge, which is where this is all coming from. That 5,56 projo needs to fragment to do what it was designed to do - otherwise, it leaves a small entry wound and a small exit wound, straight through. Fragmentation ability is directly tied to bullet speed on impact. The speed reduction of 5.56 from a 11.5" barrel down to a 10.5" barrel is the major jump, and the major loss in speed. You're already at a disadvantage shorter than 11.5", due to that drop in speed at anything under that point/length.
Now, with those reduced speeds, and when you drop under the "fragmentation speed," you need to determine what ranges you'll expect to engage targets with said short-barreled weapon. If your job is room clearing, you can do that with a pretty short barrel, and that 5.56 bullet will probably fragment in that distance. If you're taking your 7.5" 5.56 pistol out to a 300-yard engagement point, that 5.56 projo is not going to fragment at that range. You better make a vital hit with it.
Anyway, that's the background on it. More can be found in the works of Doc Roberts, and his analysis and presentations.