This thread is throwing me for a loop. I always had the understanding the 300BLK was supposed to give the same characteristics of good 556 ammo but in a shorter, more easily suppressed platform specifically for CQB/HD. If that's not the case, what exactly is 300BLK for?
Well, HD is CQB, but CQB is not, necessarily, HD.Originally Posted by Balisong
HD, in my urbanized area, with Fifties-era, thin-cedar-skinned bungalows, is not the same as HD “on the prairie,” where my late great-grandparents’ farm is located, and most neighboring structures are quite far away.
It appears that some, perhaps many, see 300BLK as being equivalent-ish to 7.62x39 and .30 WCF, and usable for the same purposes. I do remember that plenty of game was taken with the ballistically similar .300 Whisper, by influential gun writer J.D. Jones, and his followers.
I claim no great knowledge or expertise; this is just my $0.02, as I try to educate myself about the various cartridges for short-barreled ARs. (I am leaning toward acquiring a 10.5” DDM4 300BLK pistol with LAW folder and brace, as a niche weapon, not a home-defense weapon.)
I've given this a LOT of thought (like $50K in various SBR and PCC weapon systems over the years) and I think that today's answer is a little different than what I would have told you just 5 years ago. Back then, both ammunition performance from sub-10" barrels and inherent reliability issues with such weapons made me say that anything less than 10" in 5.56 was likely to be a loud, unreliable, and poorly performing waste of time. At that time, I was running 10-11.5" 5.56 platforms with either a Surefire SOCOM Mini or comparable KAC QDC/CQB; nowhere near hearing safe, but certainly much better than feeling like a icepick in the ear when firing unsuppressed indoors.
Well, things have changed a little. We have more ammo that will do the job within 100 meters from 5.56 barrels as short as 8" such as the all-copper 50 grain TSX. Even the RA556B will perform well down to ~1600 fps which gets you out to ~75 yards with a 8" barrel. So, modern ammo has addressed some of the expansion and barrier issues that come from velocity loss at very short 5.56 barrels. When it comes to mechanical reliability of the platforms, we are seeing more ultrashort and reliable 5.56 platforms such as the SCAR CQB (10") and B&T APC (8"). Unfortunately, they are very expensive.
That leaves us with a few options. Either pay the cost of a reliable, ultra-short 5.56 platform and feed it top notch ammo. Or, get a 9" 300blk or 6.8SPC AR platform and run it suppressed with something like the Silencerco Omega 9K. I have that exact 300blk package on both MCX and standard AR-PDW platforms. Their overall length is similar to a suppressed HK MP5 - very manageable. I'll tolerate the roughly 2-3" of over penetration using Barnes TAC-TX pills since those things expand wonderfully through all common intermediate barriers.
Last edited by Sensei; 01-01-2019 at 09:24 PM.
I like my rifles like my women - short, light, fast, brown, and suppressed.
This is what led to my calling it “300 WTF” for a long time.
With the correct supersonic ammo 300blk gives supperior performance to 556. Here are gel shots of the 110 grain Barnes VOR-TX (TAC-TX):
You will struggle to find 556 loads that can expand like that through auto glass or metal from a 16” gun, much less 9”. What is giving people so much heartburn with the 300blk is 1) that extra 2-3” of over penetration, 2) only a couple of loads do that well and they are all supersonic. There is no subsonic ammo that handles intermediate barriers like the TAC-TX. Personally, I have no problem with 2-3” of over penetration in a bullet that expands like that - I see it as an answer to the fattening of America...
I like my rifles like my women - short, light, fast, brown, and suppressed.
Maybe I’m missing something, but I don’t understand why anyone would ever want to use subsonic 300BLK for home defense or anything where your life is on the line. OP, maybe you are not understanding the purpose behind the caliber? The subsonic 300BLK was created for situations where being quiet was more important than anything else. It was supposed to replace the MP-5SD and depending on who you talk to, the MP-7. It’s for situations when our military personnel have to get close to something/someone without being detected, but they can switch to a mag full of supersonic ammo for times when rifle performance is needed and everyone already knows you are there.
If you are wanting the results and benefits offered by a rifle, then you use a rifle cartridge. I don’t know anyone who NEEDS to be ninja quiet during a HD scenario. Some of us use suppressors to minimize hearing damage, be able to communicate effectively, and possibly avoid hearing/mental trauma for our kids, spouses, dogs, etc. My HD rifle (5.56) has a suppressor. But it’s loaded with supersonic duty ammo. I’m not aware of anyone using a can on a 5.56 AR trying to load subs for it. Do they even make subs for 5.56?
Handguns are different. They all suck at stopping a human threat. Most people shot with handguns do survive, so using subsonic ammo in them doesn’t sacrifice performance the way you do with 300BLK. And frankly the best duty/defensive ammo these days is typically 147gr in 9mm anyway.
Bottom line – as has been stated in this thread by Doc GKR and others, there is no good reason to use 300BLK subsonic ammo against a person unless it’s all you have, or you are in JSOC/SOCOM. The only reason I have subsonic 300BLK ammo in my home is so that I can impress my friends at the range with how quiet it is – not for defending my life or my loved ones.
And one last thing… if you are worried about hearing/communication during a shooting in your home, do what many of us do. Keep electronic ear pro beside your HD weapon. Much easier than sacrificing terminal ballistics on your rifle, and much less expensive that a suppressor/stamp combo.
Do you have any more specific comments on the 6.8 SPC AR short barrel option as an option to 300 and 223/5.56? Thanks
The 6.8 SPC offers significantly superior terminal performance to 5.56 at all barrel lengths. Most high performing 6.8 SPC bullets are marginally better than the 300blk 110 grain VOR-TX / TAC-TX (black tip) at barrel lengths between 9-14”. Much like 300blk, the 6.8 SPC takes advantage of more efficient poweder burn compared to 556 allowing for shorter barrels with less velocity loss. The 6.8 SPC also has a much wider variety of high performing projectiles compared to the 300blk. Although you will find some 6.8 SBRs in the 7-8” range, most will fall between 10-12.5”. That is because most 6.8 SPC barrels use 1:10-12 twist, and you will need 10-12” of barrel length to get a full rotation for optimal stabilization.
If terminal performance from a SBR around intermediate barriers is your only criteria, my preference order would be 6.8 > 300blk >> 556.
Last edited by Sensei; 01-03-2019 at 03:59 AM.
I like my rifles like my women - short, light, fast, brown, and suppressed.
Sensei,
Can you elaborate further on current factory loads for the 6.8 SPC and their performance for self defense? I own a 6.8 rifle and have been out of the loop on guns in general for a couple of years now. I recently thought about switching to 5.56 and the AUG, but have decided to stay with 6.8 and get a short upper to put on a pistol lower before I get it tax stamped.
Problem is, I'm seeing that many of the recommended loads that @DocGKR had mentioned back when are no longer being made by companies or at least by companies I would trust. (Doubletap makes the 95gr TTSX and 100gr Accubond, but I've heard too many negatives to purchase from them.) I have about 5 boxes of older Hornady 110gr BTHP and I believe 2 or 3 boxes of old SSA 100gr Accubonds in the hotter, "Tactical" loading. I'd like to focus on one load to start purchasing, but I'm not sure where to go. I'm not super concerned about over penetration, so something like the 110gr Accubond from SSA/Nosler is ok, but I'd love to know if any testing has been done on the Hornady GMX loads or the SSA/Nosler E-Tip.
I really wish Wilson Combat had not stopped making 6.8 ammo.
Last edited by Aizen; 01-03-2019 at 11:55 AM.
Dr. Roberts published updated data on the 6.8 SPC on Light Fighter forums. The bottom line is that 90 grain Federal JSP (Gold Dot) is outstanding. The 110 SSA/Nosler Accubond is also good but deeper penetrating than the discontinued 100 grain offering. Keep in mind the Hornsby 110 grain VMAX is still available and excellent for home defense.
Last edited by Sensei; 01-03-2019 at 10:31 PM.
I like my rifles like my women - short, light, fast, brown, and suppressed.
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