re: Question about the 300 blackout..

This article has a bunch of chronographed loads, both factory and handloads, in both carbine and pistol length barrels. "Loading the 300 Whisper"..

Back in '01 I bought a 12" Contender barrel in 300/221 (it was a "300 Whisper", but couldn't be labeled as such as it wasn't made by SSK Industries.) JD Jones was the legendary gunsmith/shooter who owned SSK Industries and developed an entire series of "Whisper" cartridges. The cartridge was designed for self-defense/tactical uses in the AR 15 platform using either sub or supersonic loads. Unfortunately, this was before the AR craze. He copyrighted the "Whispers", but didn't submit them for SAAMI specifications. None of the big arms makers got behind the 300 Whisper. The 300 Blackout was developed at the perfect time w/ the AR craze and also had the support of Big Green.

My barrel has the proper fast twist (1:8") to handle both sub and supersonic loads, but I bought my to hunt w/ using supersonic loads. I've killed 2 whitetail deer w/ mine. My barrel pushed 125 gr Nosler BT's to 2250 fps and 130 gr Single Shot Pistol bullets (discontinued yrs ago) to 2200 fps. W/ the proper loads, the 300 Whisper/300 Blackout is a nice 200 yard deer gun w/ minimal muzzle blast and recoil. I even had a 20" Contender carbine barrel built to be my son's first deer gun. It's been a few years since I've hunted w/ it. Whenever I shoot it, I'm amazed how much velocity the supersonic loads get from only 17-18 grains of powder. I'd be hard pressed to find a better starter youth gun than a AR 15 carbine w/ adjustable buttstock chambered in 300 Whisper/300 BO.