Loudest Muzzle Blast

[PJgunner]

I can think of a few. Yup! The .30 carbine Ruger Blackhawk is right up there with the best (worst? ) of them.
Two more that come to mind are the Lazzaroni cartridges and my old remington 660 in .308 loaded with a stiff charge of H-335 and 150 gr. Sierras.
First the Lazzeroni. Firtst off, I fon't know whichc artridge he was working up, but when John Lazzeroni was doing his load work up for his super-hot rounds, he's sit at the far end of the benches at my range. Whenever possible, I'd sit at the farthest end away from him I could get. The shock wave from his muzzle brakes would literally blow the headphones off my head and I was about 70 feet away. Them's one bad azz cartridges.
Now my .308 was something else. I don't remember the load other than it was H-335 and a 150 gr. Sierra but the blast from the muzzle would melt solid steel and the flash, even at high noon on a bright sunshiny day would be brighter than the sun itself. The rifle wasn't all that light weight but the bark from the barrel made what recoil there was seem much more that it actually was. Restocking didn't help and it wasn't til I got a set of hearing protecters for my birthday that I realized that the pain was from the noise and not the recoil. They sure took the "OUCH" out of that rifle.
Paul B.