In terms of popularity, the .300 AAC Blackout has had quite a rollercoaster ride. When it first hit the scene in 2009, I thought that we revolutionized the AR-15 platform and put it on the same tier as traditional hunting rifles. Then, as the fad faded and some of the feeding and cycling issues started to present themselves, it started to seem like perhaps its story was within the final chapters. Fast forward to today, and the cartridge is experiencing a renaissance, as quiet evening hunts are far more prevalent, thanks to the availability of affordable thermal and digital night vision imaging devices like the Sightmark Wraith 4k Mini or its thermal counterpart. Couple that with negligible wait times for suppressors and viola, what’s old is new again, so much so that handloading the cartridge has become fashionable. I, for one, have created a dedicated station on my reloading bench for this cartridge, as I am gobbling it up like it's .22LR. Today, my ammo feeds better than most factory loads, and the process is rather streamlined, but getting it there took a little work.
For starters, it pays to start with quality dies, particularly when developing your initial load. Repeatability is key, and I think RCBS has done an excellent job of hitting this mark for generations. Recently, it started offering these in complete kits with the moniker “Supreme.” At the time of this writing, eight options are available, each including a chamber case-length gauge to confirm your cases will headspace properly and that your finished ammunition is within spec. When it comes to diagnosing feeding issues, it’s helpful to be able to rule out these possibilities, as chasing two variables is a nightmare. I also appreciate that these kits include a shell holder, as to this day I still forget to add one during checkout with nearly every die order.
Once I’ve established a good powder charge, I’ve found varying seating depth to be the secret sauce to curing finicky feeding. Yes, many bullets have crimping cannelures that seem to be telling you something, but that isn’t a hard and fast rule. Furthermore, that cannelure doesn’t take into account what cartridge the projectile will be loaded into. Pushing the bullet out further typically ensures that the tip will be inside the chamber before it is released from the magazine’s feed lips. This ensures better feeding and helps to fight off the dreaded nosedive malfunction. Use caution, though, as going too far might mean that it won’t release in time and create a failure-to-feed scenario.
Although essential, I’ve found that keeping lubrication to a minimum serves this cartridge better than slopping it on with a lube pad. Again, I turn to RCBS for this solution. Its Case Slick spray offers more than enough slip to size these cases and is easily applied ala the “Chex Mix” method: that is, spraying the walls of a plastic sandwich bag three or four times before pouring in a hundred casings and shaking it around. For such a simplistic method, it's surprisingly efficient. I like to do this before adding the brass, which ensures it stays out of the case mouths, where it can contaminate powder and even interfere with bullet seating. Removal isn’t always necessary, but for my pickiest eaters, I roll my sized cases over a rag saturated with rubbing alcohol to restore the shine.
Lastly, once my development is complete, I turn to a Lee Pro 1000 progressive press for mass production. Less than two years ago, this product underwent a major overhaul, and the result has been exceptional. Primarily intended for pistol ammo, the loading deck is tall enough for rounds like the .300 BLK and other AR-15-length cartridges. The auto-drum powder measure is built with an elastomer wiper, making it excel with stick and flake powders, as it doesn’t bind on the larger kernels nor cut them during the dispensing process. The Breech-Lock bushing system allows me to retain my die settings if I want to convert it to load something else, but with an MSRP as low as $300, keeping it set up and just buying another press is also a realistic option.
Hopefully, you’re well on your way to feeding your favorite critter-gitter, and you’ve already put some fur on the ground. If not, perhaps some of these tips and tools can get you there with less head and heartache. Thanks to better information and improvements in peripheral equipment, keeping .300 BLK alive for future generations is a realistic possibility. That’s great news for those hoping to cull the predator population, but it's bad news for foxes, coyotes, and anything else that looks to harm your livestock or targeted game species.
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