We have written this post at least 3 times on our old website as the Blackout caliber developed. While the interest in the Blackout seems to be leveled out at this point, we still received calls to order or ask about the availability of the 300 (AAC) Blackout in our break action barrels, so we figure keeping this information readily available is the best choice.
The caliber we have come to chamber as a standard is the 30-221 which is just that – a 221 Rem. opened up to the 30 caliber. This is inherently the same as JDJ's "Whisper" designation and the names can be used interchangeably when dealing with dies and new components. The "Whisper" is proprietary, so we simply don't use it.
The request to move into Blackout territory is where most of the confusion lies, and rightly so as there is variation within the Blackout's standard ammo being made for both Sub- and Supersonic shooting. As far as the name goes, it does seem that the Blackout's chamber reamer specs ( to include a longer throat than the Whisper or 30-221) is more about making their own proprietary cartridge than anything else; the brass is virtually interchangeable.
These similarities and testing we've completed in house lead us to the good news . . . the calibers are virtually interchangeable, and that means we chamber for the Blackout. Now for a couple Bullberry standards you need to realize before we delve further in . . . we don't long throat – for accuracy reasons. Calibers that are synonymous with long throats pretty much all do it to reduce chamber pressures. While that makes sense it isn't necessary in the 300 Blackout from our testing. It also makes for a horrible system when your goal is accuracy, as ours always is. No one should want a bullet to have to jump to the riflings, so we simply avoid that. Another Bullberry standard is that our typical twist rate for 30 calibers (we only use true .308" barrels) is 1:10. HOWEVER, we've been able to work with our primary barrel manufacturer (Wilson Arms' custom shop out of Branford, CT) to get access to 1:8 twist barrels at our standard caliber/twist pricing. These can still be requested as Douglas barrels, and barrels longer than 26.5" finished would need to be Douglas' products, but you now have the option to go after the extra charge or not. Douglas barrels are not purchased by us in such large quantities, so they cost us more and in turn cost you more. The Wilson barrels are of equivalent quality and expected life/wear in our experience, so the choice is yours.
The ins and outs of Blackout ammo in a Bullberry chamber:
Our 1:10 twist standard can stabilize the standard supersonic ammo lineup, 150 gr or less. However, we refuse to long throat to alleviate pressures as factory standard chambers will do. This means that you will see signs of pressure, but it is yet debatable if it's anything to panic over. Because it's faster there are limitations and without that throat relief we simply have to advise shooters to watch for the typical pressure signs: flattened primers, cratered primers, sticky opening/extraction, etc. What you'll realize if you go this route because of what you're interested in using and achieving is that you've got reduced potential for fowling. And, if you're watching pressure signs you can also creep up on powder charge . . . just be smart about it!
The subsonic ammo (and certainly subsonic handloads) put less at risk because there are fewer variables. Shooters are reporting better velocities with the heavier bullets in the tighter (1:9 or 1:8) twist rates that we offer as an upgrade. The subsonic ammo is not typically paired with the relief-style long throating, so we already like that. Slowing down those 220 gr. bullets can lead to great energy transfer downrange, though it can also be at the cost of accuracy performance. We'll stand behind our accuracy guarantee as logic allows, so don't expect perfection if you're testing the limits as warned.
All in all, there's good and not-so-good in many calibers and the Blackout is no different. As we make sporting firearms and not tactical weapons we tend to steer away from the supposed latest and greatest to hit the AR circuit, but the 300 Blackout does have at least one foot in our wheelhouse. Please call if you have any questions or would like to place an order.