Is There An Optimum Barrel Length for a Caliber?

[deerhunter99]

I believe you need barrel length in a mag to burn all the powder, I do believe that !!!

[Zero333]

I believe you need barrel length in a mag to burn all the powder, I do believe that !!!

You would be surprised if you had Quickload...

According to QL, Running numbers for a 300winmag shooting 208gr bullet, 3.500" coal,... some powders like Retumbo and RL-25 don't need more than 20" of barrel to fully burn if detonated at peak pressures (60 to 63,000 psi chamber pressure). And H-4831 powder needs 34" of barrel to fully burn in the same rifles with the same bullets and chamber pressure.

This would explain why at dusk I have never witnessed muzzle flash with Retumbo or RL-25, and seen flames with H-4831.