6.8 Factory Ammo chronograph!

Is there a list on here of the real chronographed velocities of Factory 6.8 ammo? I do not reload, & I'm finding a couple on the internet... The Upper I am looking at is a Bison 18" SPR with a 4-groove 1:11" twist. I know that "factory" velocities can be embellished a bit...

Thanks!!

If you don't have a chrono, you can shoot it out to 400 to 500 yards, and see what your come-up is to know. Otherwise, you won't know for sure what your speed is. It will be close to the box speed and err or the slower side.

Loke Chad said you really do not know without a chrony or like he said shooting at a known distance and calculating from there. Different ammo and rifles are beasts unto themselves. I have one rifle that is consitantly 5+% faster than publishrd factory data