Thanks RS39.
You never can trust factory specs. Many times the factory will use long barrels (e.g., a 20") instead of the common 16" so that their velocity looks higher.
In IPSC 3 gun competitions, your rifle ammo must make at least the minor power factor of 165. No factory specs accepted - the range officers actually shoot your amomo out of your rifle over a chronograph (at least in the bigger matches).
Power factor is determined by multiplying bullet weight X velocity and then divide by 1,000.
So, if you have a 60 grain bullet travelling at 2,850 fps = 171,000 divided by 1,000 = 171 power factor - which makes the 165 minimum easliy.
I usually shoot my AR with a 16" upper and Winchester Q3131. I get around 3100 fps with a 55 grain bullet for a power factor of 170.5. However, you MUST shoot hot AR ammo out of a 16" upper to make minor.
If you've never shot IPSC, I promise you'd like it. Check out www.uspsa.org